Neurology for Neurosurgeons
Dementia
A.
Testing
1.
Tests used to rule out other forms of
dementia:
a.
Thyroid function tests
b.
B12 – megaloblastic anemia and
posterior column deficit
c.
syphilis
d.
metabolic (kidney function, electrolyte
levels and diabetes)
e.
assess levels of heavy metals (e.g.
lead, mercury) and anaemia
f.
thiamine deficiency – Wernicke's
(ataxia, ophthalmoplegia and confusion); Korsakoff’s (confabulation and
amnesia)
2.
Normal Aging that differs from dementia
a.
Independence in daily activities
preserved
b.
Person complains of memory loss but can
provide details about incidents of forgetfulness
c.
Maintains previous interpersonal social
skills
d.
Normal MMSE
B. Alzhiemers
1.
Development of multiple cognitive
deficits manifested by both
a.
Memory impairment
b.
One (or more) of the following
cognitive disturbances:
(i)
Aphasia
(ii) Apraxia
(iii) Agnosia
(iv) Disturbance
in executive functioning (i.e. planning, organizing, sequencing, abstracting)
2.
The cognitive deficits cause
significant impairment in social or occupational functioning and represent a significant
decline from previous level of functioning
3.
The course is characterized by gradual
onset and continuing cognitive decline
C.
Dementia with
Lewy bodies
1.
occipital
lobe hypometabolism
D.
NPH
· Order
of loss: gait à urinary
incontinence à dementia
· increased ventricular size without persistent elevations in
intracranial pressure
Delerium
· Increased risk in patients with dementia
· Primary disorder of attention that subsequently affects all other
aspects of congnition
· Often represents life-threatening illness (e.g. hypoxia, sepsis,
uremic encephalopathy, electrolyte abnormality, drug intoxication, MI)
· EEG à pronounced diffuse slowing
Migraine
· Common Migraine
· Classic Migraine
o
Common migraine + aura
o
May have H/A with occasional focal
neurologic deficits that resolve completely in < 24 hrs (visual most common,
somatosensory 2nd)
· Complicated Migraine
o
Occasional attacks of classic migraine
with minimal or no H/A
o
Complete resolution in < 30 days
· Migraine Equivalent
o
Neurologic sx (N/V, visual aura, etc.)
without H/A
o
Seen mostly in children – usually
develops into typical migraine with age
· Hemiplegic Migraine
o
H/A typically precedes hemiplegia which
may persist even after H/A resolves
· Basilar Artery Migraine
o
Restricted to adolescence
o
Recurrent episodes of neurologic deficit
restricted to the vertebrobasilar system
o
Deficits: vertigo (most common), gait
ataxia, visual disturbance, dysarthria, followed by severe H/A and occasionally
N/A
o
FMH in 86%
Contraindications of triptans
1.
Familial hemiplegic migraine
2.
Uncontrolled HTN
3.
CAD
4.
Prinzmetal angina
5.
Pregnancy
6.
Ischemic stroke
7.
Basilar migraine
Abortive medications
Stepwise approach starting with the cheapest and safest
1.
Simple analgesics (e.g., acetaminophen)
2.
NSAIDs
3.
Ergot derivatives – used when migraines
last longer than 48 hours and are frequently recurrent
4.
Triptans (seroronin agonist that acts on
the serotonin 1b/1d receptor)
Seizures
· Phenytoin – DOC for partial seizures
· Juvenile Myoclonic Epilepsy
o
One of the most common epilepsy syndromes
o
Quick little jerks of the arms,
shoulders and occasionally the legs
o
Someones followed by a tonic-clonic
seizure in the contet of sleep deprivation or alcohol ingestion
· Complex partial
o
Most common type of seizure with
epilepsy in adults
o
brief episodes of impaired consciousness
(minutes), failure to respond to stimuli during the episode, staring spells,
automatisms and post-ictal confusion
o
EEG pattern is usually normal
o
Hyperventilation during the EEG cannot
stimulate a seizure (unlike petite mal)
· Absence (petite mal)
o
Brief periods of impaired consciousness
(seconds), automatisms
o
no post-ictal confusion
o
Hyperventilation during EEG reveals
generalized 3Hz spike-and-wave pattern
Parkinsonism
1.
Primary Parkinsonism
a.
Idiopathic paralysis agitans (IPA) Aka
shaking palsy
b.
Pathophysiology
i.
Degeneration of dopaminergic neurons of
the substantia nigra pars compacta
ii.
Decreases activity of the inhibitory
neurons to the internal globus pallidus
iii.
Increased activity to external globus
pallidus
iv.
Cholinergic deficit from loss of
cholinergic neurons in the nucleus basalis of meynert
c.
Dx:
i.
Clinical diagnosis needs 2 of 3 cardinal
signs
d.
resting tremor
e.
rigidity - test passive ROM
f.
bradykinesia – test active ROM and rapid
alternating movements
i.
Signs: Hypokinetic gait, postural
instability, finger tapping gets smaller, words get quicker on repitition
ii.
nonmotor sx
usually seen first: sleep, olfactory, mood
iii. orthostasis is usually a later
manifestation and a SE of park medications
g.
Rx:
i. start with MAO-B if only a slight tremor
ii.
Dopamine
Agonists (Requip, Mirapex) - younger < 60 yo and slight tremor
iii.
Benztropine
(1) best for resting tremor in patients less than age 70 (bc
anticholinergic SE below)
(2) improves tremor and rigidity but not much affect on bradykinesia
(3) Anticholinergic SE: dry skin/mouth, constipation, urinary retention,
precipitate acute glaucoma
iv.
Clozapine – used if patients have
hallucinations
v.
L-Dopa/Cardbidopa
(1) best for parkinsons but doesn’t slow disease progression
(2) increased dose gives size effects: dyskinesias, hallucinations
(3) on-time – dyskinesias (involuntary movements)
(4) Off-time – return of Parkinson symptoms
h.
DDx: Essential tremor – symmetric and can involve head
2.
Secondary Parkinsonism
a.
Olivopontocerebellar atrophy (OPCA)
i. degeneration
of neurons in specific areas of the brain – the cerebellum, pons, and inferior
olives
ii. Parkinsonism + prominent ataxia
b.
Corticobasal Degeneration
i.
Rare
ii.
Symptoms
(1) Parkinsonism
(2) Alien Hand Syndrome asymmetric jerking of limbs
(3) Apraxia – inability to
(4) Sensory cortical dysfunction (apraxia, aphasia)
c.
Progressive Supranuclear Palsy (PSNP)
i.
Triad
(1) Impaired vertical gaze
(2) Pseudobulbar palsy (mask-like facies with marked dysarthria and
dysphagia, hyperactive jaw jerk, emotional incontinence usually mild)
(3) Axial dystonia (especially of neck and upper trunk)
ii.
Differentiating from Parkinson’s disease
(1) Mask facies
(2) Do not walk bent forward
(3) Do not have a tremor
iii.
Many falls due to disequilibrium +
downgaze palsy
d.
Multiple system atrophy
i.
Shy-Dragger is no longer recognized
ii.
Parkinsonism + autonomic dysfunction (orthostatic
hypotension, abnormal sweating,
disturbance of bowel or bladder)
iii.
widespread neurological signs
(cerebellar, pyramidal, LMN)
iv.
degeneration of the lateral horn neurons
of thoracic spinal cord
v.
always consider when a patient with
Parkinsonism experiences orthostatic hypotension, incontinence or other
autonomic symptoms
e.
Drug Induced
i.
MPTP – byproduct of the synthesis of
MPPP (a meperidine analog)
ii.
Prescription drugs
(1) antipsychotics (Haloperidol)
(2) metoclopramide
(3) phenothiazine antiemetics (prochlorperazine)
f.
Structural Lesion to Basal Ganglia
i.
Tumor, abscess, infarct
ii.
Gait disturbance predominates
iii.
Tremor is rare
g.
Posttraumatic – dementia pugilistica
Essential
Tremor
· Autosomal dominant pattern may be present
· Action tremor (suppressed at rest) in the absence of additional
neurologic signs
· Amplitude of tremors typically increase at the end of goal-directed
activities
· Rx:
o
beta-blockers first line
o
primidone: an anticonvulsant that
converts into phenylethylmalonamide and phenobarbital
-
may precipitate acute intermittent
porphyria: abdominal pain, neurologic and psych sx
· DDx:
o
Parkinsons – resting tremor, rigidity,
bradykinesia
o
Spinocerebellar ataxia (SCA) – genetic
degeneration of the cerebellum; can have hand tremor but patients also have a
significant ataxic gain; presents at younger age
o
Intention Tremor (e.g. Cerebellar
stroke/lesion)
-
Can differentiate by vignette:
Essential will be younger pt with FMH of tremor
-
Cerebellar lesions will be alcoholic or
vasculopath with a tremor that gets worse as they get closer to the object
Other
Movement Disorders
Akathesia –
sensation of restlessness
Dystonia
· Co-contraction of antagonistic muscles (flexors & extensors) resulting
in twisting repetitive movements or abnormal postures
- Types:
- Generalized – DYT1 hereditary dystonia
- Focal – usually associated with a specific tast
- writer's cramp - most common focal, task specific dystonia
- blepharospasm
- cervical dystonia (torticollis) – dystonia of the sternocleidomastoid
- Spasmodic dysphonia
- affects the muscles of phonation
- often tremulous and is commonly misdiagnosed as essential tremor.
- Segmental – multiple muscles
- Drug induced: neuroleptics, metoclopramide and phenothiazine entiemetics
- Meige syndrome
- an adult-onset dystonia that predominantly involves facial muscles, causing disabling blepharospasm and oromandibular dystonia.
- Some develop spasmodic dysphonia & dystonia of the neck, trunk, arms, and legs
- Rx:
- Focal dystonia
- botulinum toxin injections (e.g. Botox)
- Diphenhydramine IV for drug induced
- Generalized Dystonia
- Anticholinergics (trihexyphenidyl (Artane) and benztropine)
- work best in children with primary generalized dystonia
- usually ineffective and poorly tolerated in adults.
- DBS – ventrolateral thalamus and internal pallidum most common targets
- DDx:
- Tourette’s – exhibits both motor & vocal tics
- Chronic Tic Disorders
- Motor or vocal tic, not both. Tics usually start at age 5 or 6 and get worse until age 12. They often improve during adulthood.
- may worsen with excitement, stress, fatigue
Tardive Dyskinesia
- chronic exposure to central dopamine blocking agents (neuroleptics, metoclopramide and phenothiazine entiemetics)
- Dx: Clinical
- Involuntary movement of the oral-buccel-lingual muscles
- Arching spasms of the back and neck
- Rx: tetrabenzene; clonazepam
Myoclonus
- random, sudden movements of a body part caused by brief muscle contractions
- most common movement disorder in the hospital
- Cortical Myoclonus
- abnormal hyperexcitability of the cerebral cortex
- mainly affects the distal upper limbs and face, which reflects the largest cortical representations of these body areas
- It is often focal, but may be multifocal, bilateral or generalized, as a consequence of intracortical and transcallosal spreading of abnormal activity
- Subcortical myoclonus – origin between the cortex and the spinal cord
- Causes
- focal – e.g. asterixis
- generalized
- acute – toxin or systemic illness
- chronic – insidious onset, likely degenerative (e.g. Alzheimer’s)
Gait
Disorders
1) Highest level disorders: Cortical-basal
ganglia-thalamocortical loop lesions
a) Absent or inappropriate corrective actions
- “falling like a log” on the pull test
b) Inappropriate interaction with the
environment
i) crossing the lower limbs when walking
ii) leaning the wrong direction when turning or
standing
iii) sitting askew on a chair or commode
c) Variable performance - Influenced greatly
by the environment and emotion
d) Hesitation and freezing (“ignition
failure”)
2) Middle level disorders: Descending motor
pathways, ascending sensory pathways, brainstem, spinal cord, and cerebellar
pathways.
a) High cervical myelopathy: numb clumsy
hands, ataxic gait or spastic gait
3) Lowest level disorders: Musculoskeletal,
neuromuscular, visual and vestibular deficits.
a) Lower-level gait disorders are disturbances
of gait produced by disease of the muscles, skeleton, peripheral nerves, and
peripheral visual or vestibular pathways.
Inactivation of the
Cerebellar Nuclei
1) fastigium - severe truncal ataxia with a
tendency to fall toward the side of the lesion
2) interpositus - classic intention tremor and
extremity ataxia on the side of the lesion
3) dentate - awkward execution of skilled
motor movements, particularly those requiring fine motor control.
Balance Disorders produced by unilateral pathology
1. Frontal
lobe lesion: patient falls
laterally away from the side of the lesion. Contralateral limb movements
may resemble cerebellar ataxia (Brun's ataxia).
2. Lesion in
lenticular nuclei (putamen and
globus pallidus): patient falls backward and laterally away from the lesion.
3. Ventrolateral
thalamic lesion: patient falls
backward and laterally away from the lesion (thalamic astasia).
4. Pusher syndrome: patient pushes himself away from the
lesion due to the misperception that his body tilted toward the lesion.
These patients have lesions in the ventrolateral thalamus and, less commonly, in
the insula and post-central gyrus.
5. Cerebellar lesion (particularly the vestibulocerebellum):
patient falls laterally toward the side of the lesion.
6. Vestibular
nucleus lesion: patient falls
laterally toward the side of the lesion.
7. Vestibular
neuritis: patient falls
laterally toward the side of the lesion
Myasthenia
Gravis
· Thymus involvement – hyperplasia or thymoma
· 50% of ocular MG are seronegative
· 80% of MG patients are Ach antibody negative but have a positive
antimuscle specific tyrosine kinase (MUSK) antibody assay
- Neonatal MG
- From maternal antibodies
- Rx: AChE inhibitor (neostigmine)
- Rx:
o
Edrophonium used for diagnosis – will
improve weakness
o
Oral anticholinesterase initially
- Tertiary amine cholinesterase inhibitors
- rivastigmine, tacrine, donepezil
- not used in MG because the readily pass the BBB
- used in Alzheimer's disease
- Quaternary amine cholinesterase inhibitors
- pyridostigmine and neostigmine
- do not pass the BBB readily and are useful for myasthenia
- Reversible ChEI - pyridostigmine act for duration of 4 hours
- Irreversible ChEI - parathion, not useful in MG and are of toxicological concern for pesticide and nerve gas exposure
o
Immunouppressive agents
§ Prednisolone – works in 1-2 weeks but long term side effects
§ azathioprine, cyclosporine – take longer to work but less side effects
o
Plasmapheresis or IV IG in seriously ill
or myasthenic crisis
o
Thymectomy long term – Ideally for those
between puberty and 60 years of age with MG that is not confined to the ocular
muscles
· DDx:
o
Lambert- Eaton – loss of DTRs;
myasthenia retains DTRs
o
Both can occur with small-cell lung
cancer
· Cholinergic Crisis
o
over-stimulation at a neuromuscular
junction due to an excess of acetylcholine or from the inhibition of the
acetylcholinesterase enzyme.
o
Causes:
§ Too
high a dosage of myasthenia gravis drugs
§ Irreversible
AChE inhibitors (nerve gas or organophosphates)
- Sx: muscles stop responding to Ach à flaccid paralysis; respiratory failure, increased sweating, salivation, miosis
· Myasthenic Crisis
o
Endotracheal intubation – if vital
capacity falls below 1.4L and/or patients looks in distress
o
Withdrawal of anticholinesterases
- Myasthenic vs Cholinergic crises
- both crises exhibit weakness, respiratory problems, dysphagia
- Cholinergic crisis also exhibits GI hyperactivity and hypersecretions
- Differentiate using edrophonium (tensilon)
- Edrophonium worsens the paralysis caused by cholinergic crisis, but strengthens the muscle in the case of myasthenia gravis
Multiple
Sclerosis
· Signs and Symptoms
o
Visual:
§ optic neuritis - Optic Neuritis - suspect in patient with central
scotoma, afferent pupillary defect, swollen optic discs, changes in color
perception and decreased visual acuity; associated with ms
§ internuclear ophthalmoplegia
o
Motor: extremity weakness and gait ataxia;
spasticity of the Les often due to pyramidal tract involvement
o
Sensory: posterior column involvement
often causes loss of proprioception; Lhermitte’s sign (electric sher puock-like
pain radiating down the spine on neck flexion) is common
o
Reflex: hyperreflexia and Babinski signs
o
GU Symptoms: urinary frequency, urgency,
and incontinence
· Diagnosis
o
No single clinical feature or diagnostic
test is adequate
o
MRI
§ Dawson’s fingers – ovoid lesions oriented perpendicular to the
ependymal surface
§ DWI should be normal, however plaques can sometimes exhibit “shine
through” so the ADC map must be checked to rule-out artifact
§ IgG bands (oligoclonal bands)
§ Seen on agarose gel electrophoresis of CSF not present in the serum
§ Not specific for MS, and can occur in CNS infections and less commonly
with strokes or tumors
· Treatment
o
Acute exacerbations
§ treatment with IV steroids
§ High dose methylprednisolone used when patients have disabling
symptoms
o
Reduce frequency of exacerbations
§ Interferon-beta – decreases the frequency of relapse and reduces
disability in patients with the relapsing-remitting form of MS
§ Cyclosporine, methotrexate, mitoxantrone – used in the progressive
form of MS
§ Plasmapheresis (may enhance immunosuppression)
§ IV IG (theoretical but not recommended)
§ Glatiramer acetate
· Decreases frequency and severity of MS exacerbations
· Synthetic mixture of polypeptides containing random combinations of
four amino acids found in myelin basic protein
· Functions by inducing suppressor T-cells that downregulate the
T-cell-mediated immune response to myelin antigens that underlies MS
Acute Disseminated Encephalomyelitis (ADEM)
• Differentiating from MS: ADEM is a
monophasic illness, early onset ataxia, involvement of deep gray matter
especially thalami, absence of oligoclonal bands
• Sx appear suddenly 1 to 3 weeks following
viral infection or vaccination and can include headache, N/V, confusion and can
progress to obtundation and coma
• Can have hemiparesis, ataxia, optic
neuritis
• Csf may have pleocytosis and elevated
protein
• Perivenular demyelination
• Rx: corticosteroid therapy
Stroke
Syndromes
Putamen
· Most common site of intracerebral hemorrhage (hypertensive hemorrhage)
· Focal neurological signs suddenly develop and gradually worsen
· Internal capsule that lies adjacent to the putamen is almost always
involved – leads to hemiparesis
· Other signs include
hemi-sensory loss, homonymous hemianopsia, stupor and coma
· eyes are deviated away fom paralytic side
Cerebellum
· Account for 16% of intracerebral hemorrhage
· Ataxia, vomiting, occipital H/A, gaze palsy, facial weakness, no
hemiparesis
Brainstem
Medulla
|
Medial
|
Lateral
|
|
Motor
|
Ipsilateral pain & temp of face
|
|
Touch
|
Contralateral pain & temp of body
|
|
Hypoglossal
|
Cerebellum
|
|
|
Vestibular system
|
|
|
Motor to pharynx/larynx
|
|
|
Horners
|
· Medial Medullary
o
Anterior spinal artery
o
XII nucleus/fibers: ipsilateral
flaccid paralysis of tongue
o
Pyramid: contralateral spastic paresis (body)
o
Medial lemniscus: contralateral loss of tactile,
vibration, conscious proprioception
· Lateral Medullary (Wallenberg syndrome)
o
PICA
o
Vestibular nuclei: vertigo, N/V, nystagmus (away from
lesion)
o
Inferior cerebellar peduncle: ipsilateral limb
ataxia
o
Nucleus ambiguous: ipsilateral paralysis of larynx, pharynx,
palate à dysarthria, dysphagia, loss of gag
o
Spinal V: ipsilateral pain/temperature loss
(face)
o
Descending hypothalamics: ipsilateral
Horner syndrome
o
Spinothalamic tract: contralateral
pain/temp (body)
Pons
|
Medial
|
Lateral
|
|
Contralateral motor
|
Pain & Temp
|
|
Contralateral touch
|
Cerebellum
|
|
Abducens
|
Vestibular system
|
|
|
Motor to face
|
|
|
Hearing
|
|
|
Horners
|
· Medial Pons
o
Paramedial Branches of Basilar Artery
o
Corticospinal tract: contralateral
spastic hemiparesis
o
Medial lemniscus: contralateral loss of
tactile/position/vibration sensation on body
o
Fibers of VI: medial strabismus
· Lateral Pons
o
AICA
o
Vestibular nuclei: vertigo, N/V,
nystagmus
o
Middle cerebellar peduncle: ipsilateral ataxia
o
Facial nucleus and fibers: ipsilateral facial
paralysis…
o
Spinal trigeminal nucleus: ipsilateral
pain/temperature loss
o
CN VIII nucleus/fibers: ipsilateral
hearing loss
o
Descending sympathetics: ipsilateral
Horner syndrome
o
Spinothalamic tract: contralateral loss
of pain/temperature
· Central Midbrain – oculomotor paresis and other CN III dysfunctions
are common, and cerebellar ataxia and contralateral hemiplegia
o
Weber – Ipsilateral CN III,
contralateral Hemiplegia
o
Benedikt – Ipsilateral CN III,
contralateral ataxia
Lacunar Infarct
· due to microatheroma and lipohyalinosis
|
Syndrome
|
Pathology
|
Presentation
|
|
Pure motor hemiparesis (most common)
|
Posterior limb of internal capsule
corticospinal & corticobulbar
|
Unilateral motor deficit (face, arm, and to lesser extent leg); mild
dysarthria
NO sensory, visual, higher cortical deficits
|
|
Pure sensory stroke
|
VPL of thalamus
|
Unilateral numbness of face, arm, trunk, leg
Dejerine-Roussy syndrome – Rare thalamic pain syndrome that may
develop late
|
|
Ataxis-hemiparesis
|
Anterior limb of internal capsule
|
Weakness that is more prominent in the lower extremity, along with
ipsilateral arm and leg incoordination
|
|
Dysarthria-clumsy hand
|
Basis pontis
|
Hand weakness, mild motor aphasia, NO sensory abnormalities
|
ACA Stroke
· contralateral motor and/or sensory deficits more pronounced in the
lower limb than upper
· urinary incontinence, gait apraxia, primitive reflexes (e.g., grasp,
sucking)
· abulia, paratonic rigidity, emotional disturbance
· deviation of the head and eyes toward lesion
MCA Stroke
· contralateral motor and/or sensory deficits (more pronounced in the
upper limb)
· conjugate eye deviation toward side of infarct (frontal eye field,
Brodmann area 8)
· homonymous hemianophia (Meyer’s loop of the temporal lobe)
· left (dominant) – aphasia
· right (nondominant) – neglect and/or anosognosia
PCA Stroke
· homonymous hemianophia
· left (dominant) – alexia without agraphia
· visual hallucinations (calcarine cortex)
· sensory symptoms (thalamus)
· third nerve palsy with pareses of vertical eye movements, and motor
deficits (cerebral peduncle, midbrain)
Internal Carotid Stroke
· Signs and symptoms of a MCA stroke
· Visual symptoms, such as amaurosis fugax
Transient
Ischemic Attack (TIA)
· associated symptoms resolve within 24 hours
Eyes look toward
stroke and away from seizure. Eyes can look away from hemorrhagic stroke?
Genetic
Syndromes
Friedreich ataxia
· most comon type of spinocerebelar ataxia
· neurologic (ataxia, dysarthria)
· skeletal (scoliosis, feet deformities)
· cardiac (concentric hypertrophic cardiomyopathy)
Spinocerebellar ataxia (SCA)
· genetic degeneration of the cerebellum; CAG repeat disorder
· dorsal column, later corticospinal, and
sometimes later spinothslamic
·
Initial
symptoms usually paresthesias in hands and feet
·
Can progress
to sensory loss, gait ataxia and distal weakness in legs
· later causes dysarthria, abnormal saccades, probable LMN findings and
UMN deficits
· Dx: DNA confirmation
Other
L5 radiculopathy
· foot drop from inability to dorsiflex the foot
· most commonly caused by peripheral neuropathy, trauma or congenital
(Charcot-Marie-Tooth disease)
· peroneal nerve or radiculopathy of any spinal roots that contribute to
the common peroneal nerve (L4-S2)
Tarsal Tunnel
Syndrome
· entrapment of the posterior tibial nerve as it passes underneath the
flexor retinaculum on the medial aspect of the ankle
· Sx: dysesthesia and numbness plantar foot
Carotidynia
· Neurological condition caused by inflammation of the carotids and the
vagus
· Pain localized to the carotid artery distribution in the neck – jaw or
neck
· Dental trauma is a common precipitant
· Diagnosis is clinical although MRI is sometimes required
Carotid
endarterectomy
· < 60% stenosis – disease can be followed every 6-12 mo with duplex
U/S
· Carotid endarterectomy (CAE) beneficial in preventing stroke
· CAE indicated for carotid
artery stenosis of 60 to 99% even when asymptomatic
· complete occlusion (100% stenosis) is a contraindication to surgery
Acute angle
closure glaucoma
· preexisting narrow anterior chamber angle is closed in response to
pupillary dilation from medications or another stimulus
· precipitating factor: dim light, anticholinergic medication, or
sympathomimetic medication
NF1
1. Diagnosis
a. Six or more café-au-lait spots or
hyperpigmented macules ≥5 mm in diameter in children younger than 10
years
b. Six or more café-au-lait spots >15 mm in
adults
c. Axillary or inguinal freckles
d. Two or more typical neurofibromas or one
plexiform neurofibroma
e. Optic nerve glioma
f. Two or more iris hamartomas (Lisch
nodules), often identified only through slit-lamp examination by an
ophthalmologist
g. Sphenoid dysplasia or typical long-bone
abnormalities such as pseudarthrosis
h. First-degree relative (eg, mother, father,
sister, brother) with NF1
2. Pathophysiology
a.
mutation in
or deletion of the NF1 gene
b.
gene product
neurofibromin serves as a tumor suppressor
3.
Incidence: 1
in 3000
4. Findings: Cutaneous, neurologic, and orthopedic
manifestations:
a.
subcutaneous
and cutaneous neurofibromas
b.
plexiform
neurofibromas
c.
Gliomas:
pilocytic astrocytomas and low-grade astrocytomas are ommon; diffusely
infiltrating astrocytomas are also seen in a subset
d.
GI stromal
tumors: lead to bleeding or obstruction
e.
Malignant
peripheral nerve sheath tumors (MPNSTs) and neurosarcomas are not uncommon in
adolescents and adults with NF1, with an approximate lifetime risk of
10%.
f.
Hypertension:
need to look for pheocromoctoma and renal artery stenosis
NF2 – bilateral acoustic neuromas and
cataracts
Restless leg syndrome
· uncomfortable sensation or urge to move legs, discomfort worse in
evening, during sleep and at rest; discomfort alleviated by movement
· Rx: dopamine agonists (e.g. pramipexole and ropinerole)
HIV
· HIV-Associated Dementia
o
Earliest sx include difficulty with
concentration, attention, and mentation
o
Forgetfulness and personality changes
begin to appear
o
Psychomotor dyfunction manifested by
poor balance and lack of coordinations follows cognitive dysfunction
o
Myoclonic jerks, postural tremor and
bowel/bladder dysfunction later eventually leading to an almost vegetative
state
o
No focal neurologic deficits
· Progressive Multifocal leukencephalopathy – multiple non-enhancing
lesions that don’t produce mass effect
· Primary CNS lymphoma – presence of EBV DNA in CSF is specific; MRI
reveals a weakly ring-enhancing mass that is usually solitary and
periventricular
· Toxoplasmosis – multiple, ring-enhancing, spherical lesions in the
basal ganglia; positive Toxoplasma serology is common in normal subjects in US
and not specific
· Cryptococcal meningitis
o
Chronic lymphocytic meningitis
o
Increases opening pressure, elevated
proteins, pleocytosis, low glucose
o
Organisms detected by india ink
HSV Encephalitis
· May present cutely (<1 week duration) with focal neurological
findings
· CSF – lymphocytosis, elevated proteins
· PCR analysis of HSV DNA in the CSF is the gold standard
· Rx: acyclovir
GBS
· Sx: initially have paresthesias à ascending
weakness à respiratory failure
· Suspect in anyone with ascending weakness and areflexia
· Supportive therapy
o
follow vital capacity – risk for
ventilator failure increases when VC falls below 1.4 L
o
monitor for autonomic instability
· DDx: Transverse myelitis
o
Suspect transverse myelitis if LP comes
back with increased WBC and increased protein
o
GBS have only increased protein
Tick-borne paralysis
· progressive ascending paralysis over hours to days
· normal CSF
Botulism
·
hyporeflexia
·
descending
symmetrical weakness
·
best
diagnosed by fecal cultures or EMG in infantile cases
Craniopharyngeoma
· bimodal distribution – childrena nd 55-65 years age group
· benign suprasellar tumor usually presents with hypopituitarism,
headaches and bitemporal blindness
Pseudotumor
· Impaired reabsorption by arachnoid villi
· Vitamin A and isotretinoi can predispose
Brain Death
· Absent brainstem reflexes: cough, corneal and gag
· Absent oculovestibular reflex
· No spontaneous breathing when ventilator is turned off for 10 minutes
· Confirmation by at least two physicians
Motor Neuron Disease
· Degenerative Diseases
o
Mixed UMN & LMN: amyotrophic lateral
sclerosis (ALS)
o
UMN: primary lateral sclerosis
o
LMN: progressive muscular atrophy (PMA)
and spinal muscular atrophy (SMA)
Myelitis – aka Acute Transverse Myelitis
· Etiologies: infectious (polio, viral, fungal), autoimmune (MS),
idiopathic
· Myelitis indicates inflammation of the spinal cord
· Myelopathy indicates compressive, toxic or metabolic etiologies
· Sx at the time of maximum deficit (90%+)
o
Sensory deficit or paresthesias
o
Muscle weakness
o
Sphincter disturbance (hesitancy,
retention, overflow)
· Evaluation
o
CSF contained elevated protein or
pleocytosis in 62% of patients
o
MRI
· Rx: high-dose steroids may have some efficacy
Corticosteroid-induced myopathy
· Acute: diffuse muscle weakness and rhabdomyolysis
· Chronic: proximal muscle weakness without significant pain
Hypokalemia = muscle weakness, myalgias
Neurosarcoidosis
· Neurologic involvement of sarcoidosis
· exaggerated cellular immune response
· Primarily involves the leptomeninges
· Sx:
o
May produce multiple cranial nerve
palsies
o
Diabetes insipidus is the most common
neurologic manifestation
· Findings
o
ACE abnormally elevated
o
CXR reveals hilar adenopathy
Vascular
dysautoregylstory encephalopathy
- Posterior encephalopathy syndrome (PRES)
- Group of widespread vasogenic brain edema with predominance in the parietal and occipital regions
- Small number go onto infarction
- Associated conditions
- Hypertensive encephalopathy
- Preclampsia
- Infection, sepsis, shock
- Autoimmune disease
- Chemotherapy
- Organ transplantation
- Cyclosporine neurotoxicity
- Rx: treat underlying cause (i.e. Control HTN, hold immunosuppressive or chemo, delivery of the placenta, etc.)
- Uremic encephalopathy
- Symmetric edema in basal ganglia with severe cases developing focal infarcts with or without hemorrhage
- Include
- Uremia
- Glomeruli nephritis
- HUS
- TTP
- Crossed cerebellar Diaschisis
- Hypo metabolism of cerebellar cortex contra lateral to a cerebral hemispheric lesion
- Theory: due to disconnection of the cerebro-ponto-cerebellar pathways
Vasculitis
- Group of disorders characterized by inflammation and necrosis
- Type of CNS involvement
- Acute encephalopathy
- Seizure
- Cranial nerve
- Spinal cord
- ICH, SAH
- Those that affect the CNS
- PAN - every organ except lung and spleen
- Temporal arthritis
- Takayasu's
- Wegener 's
- Lymphomatoid granulomstosis - rare; affects lungs, skin and CNS
- Behçet's disease - relapsing ocular lesions and recurrent oral and genitsl ulcers
- Isolated angiitis of the CNS
Polymyalgia Rheumatica
·
pain is prominent finding; not weakness
- Aching and morning stiffness in shoulder and pelvic girdle lasting > 1 month
- Rx: low dose steroids or NSAIDs
Fibromuscular
Dysplasis
- Renal artery most common involvement; internal carotid 2nd
- Sx: Unilateral headaches
Syncope/Vertigo
A.
Evaluation: passing out (syncope) vs
dizziness (vertigo)
B.
Terms
1.
Syncope
a.
Presyncope: patient feels as if they are going to black
out”; manifestation of cardiovascular disease
b.
Cardiogenic syncope
(i)
Acute without any provocation or
premonitory sx (e.g. N/V, sweating…)
(ii) Not
associated with change in position
c.
Orthostatic hypotension
(i)
Should be evaluated for with every
patient with syncope/vertigo
(ii) Common
causes – dehydration, heart failure, medications (e.g., antihypertensives),
Parkinson disease, peripheral neuropathy (e.g., diabetic autonomic neuropathy)
2.
Vertigo: illusionary feeling of head
movement
a.
Types
(i)
Central Vertigo – brainstem or
cerebellar
(ii) Peripheral Vertigo – ear canal or inner ear
b.
Vestibular Neuritis
(i)
acute vertigo with horizontal nystagmus
beating away from the affected nerve; nystagmus may have a torsional (rotary)
component
(ii) no
disturbance of hearing
(iii) Patients
are usually able to stand and walk although they commonly veer or stagger
toward the affected ear.
3.
Other
a.
Seizure: tongue biting, urinary
incontinence
b.
Gait unsteadiness: loss of vestibular,
proprioceptive, cerebellar or motor function
c.
Dizziness: sensation of imbalance and
unsteadines
d.
Motion sickness: sensory conflict;
visual input conflicts with vestibular input
C.
Differential Diagnosis by Age
1. Elderly
a.
Benign positional vertigo
(i)
nystagmus and vertigo when affected ear
is down (as during the Hallpike-Dix maneuver)
(ii) may
exhibit all types of nystagmus depending in which semicircular canal is
involved
(iii) Rx:
Epley maneuver
b.
Labyrinthine ischemia
c.
Toxic vestibulopathy
d.
Vertebrobasilar ischemia – PICA strokes
can mimic peripheral vestibular disease (pseudovestibular syndrome)
e.
Viral labyrinthitis
2. In
Young Adults
a.
Ménière syndrome
b.
Viral labyrinthitis
c.
Traumatic vestibulopathy
d.
Toxic vestibulopathy
e.
Migraine
D. In
Children
a.
Benign paroxysmal vertigo
b.
Migraine
c.
Otitis media
Nystagmus
o
slow phase is to the pathologic side;
fast phase pulls eye back to normal
o
Central - Nystagmus changes direction
depending on which direction the patient looks
o
Peripheral - nystagmus always in same
direction irrespective of where patient looks
o
Stroke is the exception
Concussion
1.
Any patient who experiences loss of
consciousness should have a head CT
2.
Sports: only grade 1 should be able to
return to play
3.
Postconcussion syndrome (PCS)
a. 90% of patients experience H/A and dizziness for at least a month
b. 30-80% develop PCS
i.
irritability, depression, insomnia, subjective
intellectual dysfunction
ii.
peak of sx intensity is 1 week; most pts
are sx free by 3 mo
4.
Grading
|
Grade
|
AAN System
|
|
1 (Mild)
|
1.
transient confusion
2.
no LOC
symptoms resolve < 15 min
|
|
2 (Moderate)
|
As above
Symptoms last > 15 min
PTA is common
|
|
3 (Severe)
|
Any LOC
|
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