Neurology/Neurosurgery Flashcards
1
Q
Where are post-dural puncture headaches?
A
Bifrontal or Occipital
2
Q
What positioning tends to make post-dural puncture headaches feel better? Worse?
A
Better when lying down (reduces gravity forces, allowing better access of CSF to brain)
Worse when upright (gravity reduces CSF available in brain area)
This is opposite compared to IIH (pseudotumor cerebri)
3
Q
What are the treatment options for post-dural puncture headaches?
A
Acute - IV fluids
Persistent/Severe - Epidural blood patch
4
Q
How often do migraines present with auras? What is the classic aura?
A
15%
Bilateral homonymous scotoma (darkening) with bright, flashing, crescent-shaped images with jagged edges for 10-20 min
5
Q
What are some common causes for migraines?
A
Inherited - AD incomplete penetrance
Menstrual - estrogen withdrawal
Serotonin - depletion
6
Q
What are the symptoms of a migraine?
A
Prodromal - excitation/inhibition of CNS
Severe unilateral, throbbing headache that may last 4-72 hours with nausea and vomiting, photophobia, and increased sense of smell
7
Q
How can migraines be treated?
A
Prophylaxis - Propranolol (beta-blocker) > Amytriptyline (TCAs) > Verapamil (Ca2+ channel blocker) > valproic acid (anticonvulsant), methylsergide
Acute - Sumatriptan or Dihydroergotamine (DHE) (5-HT agonist)
8
Q
Where are tension headaches?
A
Diffuse across scalp, concentrated in temples, or concentrated in occipital region
9
Q
What are the most common associations with tension headaches?
A
Depression, anxiety, or stress
10
Q
How are tension headaches treated?
A
Prophylaxis - Stress reduction
Acute - Acetaminophen/NSAIDs
11
Q
What are the symptoms associated with temporal arteritis?
A
Headache, visual impairment (25-50%), jaw pain when chewing, tenderness, over temporal artery, absent temporal pulse, polymyalgia rheumatic (40%)
12
Q
How often does temporal arteritis include the ophthalmic artery? What is seen?
A
25-50%
Optic neuritis
Amaurosis fugax (monocular blindness from lack of blood flow to retina from blood clot from carotid artery traveling to retinal artery)
Blindness
13
Q
What is amaurosis fugax?
A
Monocular blindness from lack of blood flow to retina from blood clot from carotid artery traveling to retinal artery
14
Q
How is temporal arteritis treated?
A
High-dose prednisone with IV steroids if visual loss
-Do not wait for biopsy results from temporal artery if suspected
Treat for 4 weeks, and maintain with steroids for 2-3 years
ESR for effectiveness
15
Q
Where are cluster headaches?
A
Unilateral periorbital pain
16
Q
What has been found to make cluster headaches worse?
A
Alcohol
17
Q
When do cluster headaches tend to occur?
A
A few hours after the patient falls asleep, awakening the patient, and lasting for 30-90 minutes
18
Q
What symptoms are associated with cluster headaches?
A
Nausea without vomiting, ipsilateral conjunctival infection, lacrimation, nasal congestion, rhinorrhea, forehead/facial sweating, miosis, ptosis, and eyelid edema
19
Q
How are cluster headaches treated?
A
Prophylaxis - Verapamil or Steroids
Acute - O2 or Sumatriptan
20
Q
What are the most common patients for cluster headaches?
A
Males (80%)
21
Q
What are the most common patients for migraines?
A
Women
22
Q
What are the most common patients for temporal arteritis?
A
> 50 year old women
23
Q
What causes pseudotumor cerebri?
A
Increased resistance to CSF reabsorption at arachnoid villi
24
Q
What are the most common patients for pseudotumor cerebri?
A
Young obese women
25
What symptoms are associated with pseudotumor cerebri?
```
Bilateral papilledeman without mass
Headache
Elevated CSH pressure
Deteriorating vision
Slit-like ventricles
Normal scan
```
26
What positioning tends to make pseudotumor cerebri headaches feel better? Worse?
```
Sitting up (gravity helps pull some CSF away from the brain)
Laying down (the loss of gravitational force redistributes the liquid back onto the brain and eyes)
Leaning forward can also make vision loss greater
```
27
What is the most common cause of subarachnoid hemorrhage?
Congenital berry/saccular aneurysm rupture
28
How are subarachnoid hemorrhages diagnosed?
Noncontrast CT
- If no papilledema and CT is negative, but the clinical suspicion is still high, do a lumbar puncture
- Xanthrochromia (yellow color) is gold standard of lysis from RBC in CSF for subarachnoid hemorrhage
29
What is the first step after subarachnoid hemorrhage is diagnosed?
Cerebral angiography
30
How are subarachnoid hemorrhages treated?
Surgical - clipping
| Medical - bed rest, stool softeners, analgesia, IV fluids, HTN - Ca2+ channel blocker
31
How effective is lowering hypertension in cerebral infarction from post-subarachnoid hemorrhage? Why?
Lowers incidence by 1/3rd
| Decreases vasospasms
32
What is a major complication from subarachnoid hemorrhage?
Cerebral salt wasting/SIADH -> Hyponatremia
33
What is the most common cause of viral encephalitis?
Herpes simplex
34
What symptoms are associated with viral encephalitis?
```
Fever
Headache
Depressed consciousness
Neurological signs
Focal seizures
Slow wave activity on EEG
```
35
What symptoms are associated with viral meningitis?
Fever
Headache
Meningial signs (nuchal rigidity)
No impaired consciousness
36
What CSF findings are associated with viral meningitis?
Increased lymphocytes
Increased proteins
Normal glucose
Normal opening pressure
37
What symptoms are associated with bacterial meningitis?
Fever
Nuchal rigidity
Change in mental status
38
What CSF finds are associated with bacterial meningitis?
Increased PMN
Increased protein
Decreased glucose
Increased opening pressure
39
How are neonates with meningitis treated? What do they probably have?
Cefotaxime + Ampicillin + Vancomycin
GBS
40
How are children >3 months with meningitis treated? What do they probably have?
Cefotaxime + Vancomycin
Neisseria meningitides
41
How are adults with meningitis treated? What do they probably have?
Cefotaxime + Vancomycin
Streptococcus pneumoniae
42
How are elderly with meningitis treated? What do they probably have?
Cefotaxime + Ampicillin + Vancomycin
Streptococcus pneumoniae
43
How are immunocompromised with meningitis treated? What do they probably have?
Unknown
Listeria monocytogenes
44
What is done clinically if meningococcus is diagnosed in a community?
Prophylactically treat all close contacts with rifampin or ceftriaxone
45
If bacterial meningitis is suspected, what are the steps done?
1st) Draw blood cultures
2nd) CT
3rd) LP if CT allows
4th) Empiric antibiotics, + steroids if cerebral edema
46
What are the steps for stroke therapy?
1st) Non-contrast CT
2nd) ECG
3rd) CXR
4th) CBC/PT/PTT/CMP
5th) Carotid endarterectomy if eligible
6th) tPA if eligible
7th) Supportive with airway, O2, and IV fluids
47
What are the criteria for tPA?
>18 years old
Clinical diagnosis of stroke with stroke score < 22 (NIH)
Onset of stroke was known to be < 3-4.5 hours
```
BP < 185/110
Not a minor stroke
No seizure at onset of stroke
Not taking warfarin
PT < 15 or INR < 1.7
Not taking heparin within 48 hours with elevated PTT
Platelets > 100,000
Blood glucose > 50 and < 400
No acute MI
No prior intracranial hemorrhage, neoplasm, AVM, or aneurysm
No major surgical procedures within 14 days
No stroke or head injury within 3 months
No GI or GU bleeding within 21 days
No lactation or pregnancy within 30 days
```
48
What is an indicator for a carotid endarterectomy?
>70% stenosis in symptomatic patients
| -if no symptoms, reduce atherosclerotic risks and use aspirin
49
What can cause a Wallenberg syndrome? What are the symptoms?
Vertebral artery dissection or PICA occlusion
Lateral medullary ischemia
- ipsilateral ataxia, vertigo, sensation to pain and temperature of the face, and cranial nerve weakness (dysarthria, dysphagia, dysphonia, facial muscles, and tongue)
- contralateral motor weakness and sensation to pain and temperature of extremities
- Horner's with miosis, ptosis, and anhydrosis
- palatal myoclonus
50
What is the most common ischemic stroke?
MCA occlusion
51
What symptoms are seen in a MCA occlusion?
Contralateral hemiplegia and hemisensory loss
| Aphasia (if dominant hemisphere) or Apraxia, contralateral body neglect, and confusion (if non dominant hemisphere)
52
How does a thrombotic stroke and embolic stroke presentation differ? How do these differ from an intracranial hemorrhage? Finally, TIA?
Thrombotic usually take a little more time to experience neurological deficits, often waking up and experiencing deficits that get worse as time continues
Embolic are rapid onset with maximum deficits initially
Hemorrhage has abrupt pain and neurologic deficits, that will also worsen steadily over 30-90 minutes; has stupor, vomiting, increased intracranial pressure, and eventually coma
Transient ischemic attack is a focal deficit that lasts minutes to hours (1-24 hours) that resolves spontaneously; usually always has ipsilateral amaurosis fugax and/or unilateral hemiplegia/clumsiness
53
What is a TIA?
Transient ischemic attack is a focal deficit that lasts minutes to hours (1-24 hours) that resolves spontaneously
Usually always has ipsilateral amaurosis fugax and/or unilateral hemiplegia, hemiparesis, weakness, or clumsiness < 5 minutes
54
How can you tell a TIA apart from a vertebrobasilar system problem?
TIAs have vision and motor deficits that affect one side
Vertebrobasilar affect both eyes, vertigo, ataxia, diplopia, loss of consciousness/temporary amnesia
55
Why are TIAs clinically important?
They are often precursors to strokes
56
How can TIAs be diagnosed?
Carotid duplex sonography
57
How can TIAs be treated?
Prophylaxis - aspirin or antiplatelet medications
Acute - heparin
58
How does Broca's aphasia present?
Non-fluent (broken sentences)
Abnormal repetition (can't mirror your words)
Good comprehension (follows commands)
Abnormal naming
59
How does Transcortical motor aphasia present?
Non-fluent (broken sentences)
Good repetition (mirrors words)
Good comprehension (follows commands)
Abnormal naming
60
How does Wernicke's aphasia present?
Fluent (word salad)
Abnormal repetition (can't mirror your words)
Abnormal comprehension (can't follow commands)
Abnormal naming
61
How does Transcortical sensory aphasia present?
Fluent (word salad)
Good repetition (mirrors words)
Abnormal comprehension (can't follow commands)
Abnormal naming
62
How does Conduction aphasia present?
Fluent (word salad)
Good repetition (mirrors words)
Good comprehension (follows commands)
Abnormal naming
63
What are the most common patients for multiple sclerosis?
20-40 year old white women with acute exacerbations and remissions
64
What symptoms are found with multiple sclerosis?
Optic neuritis - monocular vision loss, pain on eye movement, central scotoma (darkening), decreased pupillary light reflex
Internuclear ophthalmoplegia (MLF lesion) - ipsilateral palsy of medial adduction, horizontal nystagmus of contralateral abduction
Scanning speech
Lhermitte phenomenon - neck flexion produces electric fatigue in spine, legs, or arms
65
What is Lhermitte phenomenon?
Finding in multiple sclerosis
Flexion of neck produces electric fatigue in spine, legs, or arms
66
What are the criteria for multiple sclerosis diagnosis?
Clinical - Two episodes and two white matter lesions
Lab - Two episodes, one white matter lesion on MRI, and abnormal CSF (oligoclonal bands of IgG)
67
What electrophysiologic phenomenon may occur with multiple sclerotic patients?
Visual impulses are delayed by 30-40ms
68
How can white matter lesions be seen in multiple sclerosis?
T2 MRI
69
How is multiple sclerosis treated?
Maintenance - glatiramer acetate (4 AA-myelin basic protein decoy)
Spasticity - baclofen, IFN-beta, natalizumab (PML-risk), cyclophosphamide
Pain - carbamazepine or gabapentin
Acute - high dose IV steroids
70
What cranial nerve can be involved with GBS?
CN VII
71
What clinical findings are seen with GBS?
Ascending paralysis and weakness with intact sensation
Symmetric
Respiratory arrest
Loss of deep tendon reflex
72
How can GBS be diagnosed?
CSF - elevated protein, normal cell count
| Decreased motor nerve conduction velocity
73
How can GBS be treated?
Plasma exchange and IV Ig
Do not give steroids
74
What infections can lead to GBS?
Viral
Mycoplasma
Campylobacter jejuni
75
Where does demyelination occur in vitamin B12 deficiency?
Posterior columns, lateral corticospinal tracts, and spinocerebellar tracts
- loss of position/vibratory sense in LE
- ataxia
- UMN signs (increased DTR, spasticity, Babinski+, weakness)
- -GU/GI incontinence
- -Impotence
- -Dementia
Can look like Lou Gherigs (subacute combined degeneration)
76
What is the most classical symptom of lead toxicity?
Foot drop
77
What damaged muscles would caused foot drop?
Tibialis anterior tendon and peroneal nerve palsy (or sciatic)
78
What is the most common cause of carpal tunnel syndrome?
Peripheral neuropathy
79
What is the earliest sign of carpal tunnel syndrome? The late sign?
Weakness in the thumb (also nocturnal pain, numbness, or tingling in the hand or forearm)
Wasting of thenar eminence
80
How can carpal tunnel syndrome be diagnosed?
Tinel's sign - percussing over nerve sends shock down length of the nerve
Phalen's sign - pushing dorsal surfaces of both hands against each other for 30-60 seconds; if patient cannot hold that long due to pain, it is positive
Electromyography - reduced nerve conduction velocity
81
What can lead to some peripheral neuropathies?
Genetics
Endocrine (DM, hypothyroidism, uremia)
Nutritional deficiencies (B1, B6, B12, E)
Toxic (lead, heavy metals, organophosphates, hexane)
Infectious (leprosy, Lyme, diphtheria, HIV)
Drug (cisplatin, vincristine, amiodarone, isoniazid, metronidazole, perhexeline, and thalidomide)
Autoimmune (RA, PAN, Churg-Strauss, Lupus)
Malignancy
Trauma
Idiopathic
82
What are the most commonly involved cervical radiculopathy?
C6 and C7
| -herniated disk, spinal stenosis, degenerative disk disease
83
Between C5 and C6, what nerve is coming out? L4 and L5?
If the disc bulges between C5 and C6, what nerve is affected? If the disc bulges between L4 and S1, what nerve is affected?
C6
L4
C6
L5 (which is coming out of L5 and S1; this is because the nerve travels up one before exiting)
84
What are the most commonly involved lumbar radiculopathy?
L5 and S1 herniated disc
Sciatica is the most common problem, which is a sharp or burning pain that shoots down the leg
85
What can be used to treat Alzheimer's?
Cholinesterase inhibitors
- donepezil (aricept)
- tacrine (cognex)
- rivastigmine (exelon)
- galantamine (reminyl)
NMDA receptor antagonist
-memantine
86
What are the normal symptoms found in normal pressure hydrocephalus?
Abnormal gait
Urinary incontinence
Dementia
"Wobbly, wet, and wacky"
87
What is clinically seen in normal pressure hydrocephalus?
No papilledema
Normal CSF opening pressure - but may improve patient's symptoms
CT or MRI may show enlarged ventricles
88
How is normal pressure hydrocephalus treated?
Surgical CSF shunting
89
What is Wernicke encephalopathy?
Ophthalmoplegia
Ataxia
Global confusion
Nystagmus
90
How do you approach treating alcoholic patients? Why?
Always give thiamine, then glucose
| -Giving glucose only may miss Wernicke encephalopathy in an alcoholic that is thiamine deficient
91
What is Korsakoff psychosis?
Mental status changes
Confabulation
Anterograde amnesia
Retrograde amnesia
92
Where are peripheral vertigo lesions found?
Cochlear or retrocochlear
93
What symptoms are seen in peripheral vertigo? Central vertigo?
```
Sudden onset
Tinnitus
Hearing loss
Severe intensity
Nausea and vomiting
Nystagmus unilateral
Falls to ipsilateral side
```
Brainstem symptoms (weakness, hemiplegia, diplopia, dysphagia, facial numbness)
Gradual onset
Mild intensity
Mild nausea and vomiting
Mild nystagmus
Nystagmus is multidirectional and vertical
94
What are the most common patients with benign paroxysmal positional vertigo?
>60 year old patients
95
What is the most common finding of BPPV?
Geotropic nystagmus with ear down
96
How is BPPV diagnosed?
Dix-Hallpike maneuver - laying down of patient and rotating head with ear down causes nystagmus
97
How is BPPV treated?
```
Waiting
Vestibulosuppressant
Vestibular rehabilitation
Canalith repositioning
Surgery
```
98
What is Meniere's?
An increase of fluid in the labyrinth, causing symptoms
- vertigo
- nystagmus
- hearing loss
- 10% genetic
Last minutes to hours (20 minutes medium)
99
What causes acute labryrinthitis?
Viral
100
What is an ototoxic drug?
Aminoglycosides
101
What is bilateral acoustic neuroma indicative of?
Neurofibroma Type 2
102
What are three common central vertigo-causing diseases?
Multiple sclerosis
Cerebrovascular (TIA, Vertebrobasiliar insufficiency, PICA obstruction)
Migraine
103
What are the most common drugs to give for absence epilepsy?
1st) Ethosuximide
| 2nd) Valproic acid
104
What are the most common drugs to give for status epilepticus?
1st) Lorazeoam
2nd) Fosphenytoin
3rd) Phenobarbital
4th) Midazolam/Propofol
105
What is the most common patient for juvenile myoclonic epilepsy?
Puberty
106
What can make juvenile myoclonic epilepsy worse?
Sleep deprivation
| Alcohol
107
What is the EEG for juvenile myoclonic epilepsy?
1-3 4/6Hz spikes preceding a slow wave that lasts 1-20 seconds
Absence seizures may be present
Myoclonic jerks often have 5-20 10/16Hz spikes before the slow wave
Epileptic discharges may persist briefly after clinical activity has ceased
108
How long do you treat juvenile myoclonic epilepsy? What is the most common medication?
For life
Valproic acid
109
What is the most common focus of an intractable seizure?
Temporal lobe
110
What can be seen in an MRI of a long-standing epilepsy?
Cortical dysplastic lesions
| Unilateral atrophy of amygdala and hippocampus
111
What are the first and second most common reasons for seizures in the elderly?
1st) Acute stroke (cerebrovascular)
| 2nd) Alzheimer's (degenerative)
112
How often are the temporal or frontal lobes included in resection for epilepsy control? How often does temporal lobe resection achieve cure?
80%
66%
113
What is mesial temporal lobe epilepsy?
Hippocampal sclerosis associated seizures
114
How often can mesial temporal lobe epilepsy be treated with surgery, and what is the procedure?
70%
Mesial lobe resection
115
What has corpus callosum transection been used in children to treat?
Atonic and tonic-clonic seizures
116
What is seen in complex partial epilepsy?
Impaired consciousness
Postictal confusion
Automatisms
Olfactory and gustatory hallucinations
117
What are automatisms?
Purposeless, involuntary, repetitive motions; seen in complex partial epilepsy
118
What are some early signs of uncal herniation?
Dilation of pupil of ipsilateral eye
Contralateral hemiplegia
*Can be ipsilateral hemiplegia instead due to Kernohan's notch - this causes a false impression of the side of the lesion
119
What is Kernohan's notch?
The compression of the contralateral cerebral peduncle against the tentorium from an uncal herniation; this causes the crossing motor fibers going from the cortex to be ipsilateral to the lesion to be weak, which is paradoxical to normal uncal herniations
120
What are some late signs of uncal herniation?
Loss or reflex movements in contralateral eye
Bilateral decerebrate posturing
Central neurogenic hyperventilation
121
What is the definition of coma?
GCS of 8 or less for more than 4 weeks
122
When is intubation necessary when dealing with GCS?
With a GCS less than 8
123
What is common in a persistent vegetative state?
Unawareness of self
Breathes spontaneously
Has cycles of eye opening and closing
124
What are the timelines of vegetative states?
When a coma lasts pasts 4 weeks - vegetative
| Lasts 12 months after head injury or 6 months after any other insult - irreversible, permanent vegetative
125
What are the seven criteria for brainstem death?
```
No pupillary response
No corneal response
No vestibuloocular response
No motor response in CN distribution
No gag response
No respiratory reaction to hypercapnia
Two exams by two different doctors
```
126
What is the vestibuloocular response?
Cold water in ear will cause head and eyes to tilt away
Warm water in ear will cause head and eyes to tilt towards
COWS = cold - opposite, warm - same
127
What are some things that must be done for accurate brainstem death testing?
Metabolites and drugs must be ruled out
Retest after 24 hours
Temperature must be >35degC
Identify the coma etiology
128
What are some common features of narcolepsy?
Cataplexy
Sleep paralysis
Hypnagogic hallucinations
Sleep onset REM
129
How fast is REM achieved in narcolepsy?
10 minutes
130
What are some treatments for narcolepsy?
Methylphenidate or dexamphetamine
| Modafinil (Provigil)
131
If there is high clinical suspicion for myasthenia gravis, but negative for AChR Ab, what is possible?
Anti-MuscarinicSK Ab
132
What are used to diagnose myasthenia gravis?
Edrophonium (Tensilon) - give atropine beforehand and have crash cart nearby for bradycardia
Electrophysiology
CT for thymomas
133
How is myasthenia graves treated?
```
Anticholinesterases (pyridostigmine, neostigmine)
Corticosteroids
Immunosuppressants (azathioprine)
Plasmapheresis
IV Ig
Thymectomy
```
134
What are the symptoms for Parkinson's?
```
Bradykinesia
Resting tremor (fine)
Cogwheel rigidity
Impairment of postural reflexes
Micrographia
Hypophonia
Festinating gait
Masked facies
```
135
What are the treatments for Parkinson's?
Selegiline (MAO-B inhibitor) and Entocapone (COMT inhibitor)
Benztropine (anticholinergics)
Amantadine (releases dopamine) - can cause livedo reticularis
Bromocriptine, ropinirole, pramipexole (dopamine agonist)
Levodopa, carbidopa (Sinemet) (dopamine) - can cause hallucinations early and dyskinesia later
136
What is livedo reticularis?
Side effect of amantadine
Lace-like purplish rash of the skin
137
What treatments for Parkinson's can cause serious side effects?
Amantadine and levodopa/carbidopa (Sinemet)
138
How does a resting tremor present?
Present when limb fully supported against gravity
Parkinson's
139
How does an action tremor present?
During any voluntary muscle contraction
140
How does a postural tremor present?
During maintenance of a particular posture
Benign essential tremor or physiologic tremor
141
How does kinetic tremor present?
During any type of movement
142
How does intention tremor present?
Exacerbation of kinetic tremors when a planned movement nears its completion
Cerebellar
143
How does a task-specific present?
During a particular skilled action
144
What is benign essential tremor?
Postural tremor syndrome that predominates in the upper limbs that 50% gets better with alcohol
145
How can benign essential tremor be treated?
50% respond to alcohol...
Primidone, propranolol, or topiramate
-primidone can cause acute intermittent porphyria (colicky abdominal pain)
146
How does herpes encephalitis present?
With hemorrhagic lesions in the basal frontal and temporal lobes
147
How often is herpes encephalitis fatal?
30%, with significant morbidity in a proportion of survivors
148
How can herpes encephalitis be diagnosed?
CSF examination for HSV DNA with PCR
| MRI
149
How can herpes encephalitis be treated?
Acyclovir
| Dexamethasone
150
What is seen in CSF for pseudotumor cerebri?
Normal cells, normal glucose, normal protein, but >200 pressure
151
What is the first, second, and third most common causes of death in the US?
1) Cardio/Cerebral vascular disease
2) Cancer
3) Trauma
152
In Australia, what percentage of deaths are neurotrauma? Neurotrauma from road traffic?
3.5%
65%
153
Why are the terms primary and secondary brain injury becoming blurred and obsolete?
Primary brain injury was defined as the initial damage that was irreversible, while secondary was preventable damage with treatment; now, treatment of the primary damage is being treated and being reversible - therefore the terms are not as concrete anymore
154
Is direct trauma more impressive in penetrating or blunt trauma?
Penetrating; blunt is widespread and lessened
155
What is cerebral contusion?
Bleeding that occurs under the frontal and temporal lobes from sliding across the floor and striking the sphenoid ridge and frontal bones OR bleeding from contrecoup from the opposite pole of the trauma; this results in a lacerated hemorrhagic brain or a burst temporal lobe
156
In addition to contusion damage, what may rotational damage cause from blunt trauma?
Shearing of axons and myelin sheathes, as well as resulting in petechial hemorrhages is the upper brainstem, cerebrum, and corpus callosum; retraction balls or microglial scars will be seen
157
If a patient lives for a number a months after a blunt trauma, what can be seen in postmortem?
Degeneration of myelin
158
What is a subfalcine hernia?
When the medial surface of the hemisphere may be pushed under the falx
159
What herniations can cause 3rd nerve palsy?
Uncal and hippocampal
160
What are the three ways in which a trauma may cause hydrocephalus?
1) Blood blocking the 4th ventricle
2) Swelling in posterior fossa
3) Subarachnoid hemorrhage obstructing absorption of CSF
161
How is concussion defined?
Instantaneous loss of consciousness
| Retrograde amnesia, that may last less than one day
162
What are the most commonly affected cranial nerves from blunt trauma? How is this possible?
Olfactory nerves
Fracture of the anterior cranial fossa or brain movement (blow back of the head) that tears the delicate nerve rootlets of cribriform
163
What may cause deafness in head trauma? Vertigo and nystagmus?
Fracture of petrous temporal bone
- hemotympanum (conductive)
- inner ear or nerve damage (sensorineural)
- vestibular nerve damage
- cochlear damage
* both often resolve in a few months
164
What are the main injuries that could happen from a petrous temporal bone fracture?
Deafness
Vertigo
Nystagmus
Facial paralysis (delayed or immediate)
165
Why is CN VI easily interrupted?
It has a long course into the Dorello canal
166
What nerve is infrequently injured by direct trauma?
CN II
167
What may be a false external visual indicator of head trauma?
Extent of scalp lacerations
168
What three portions of the neurological examination should have special emphasis in head trauma?
1) Conscious state
2) Pupillary size and reaction
3) Focal neurological signs in extremities
169
Why is it difficult to decipher trauma to the eye? How can it be told apart from the other pathology?
It results in a dilated pupil, just like a CN III palsy
As time progresses, the CN III palsy pathology pupil will become unresponsive to light, as well as the contralateral eye dilating and becoming unresponsive; this is absent in trauma to the eye
170
Describe gaze center lesions
Lesions cause the contralateral gaze center to overact
Frontal cause ipsilateral eye deviation
Pontine cause contralateral eye deviation
171
How are gaze center lesions diagnosed? What is a contraindication?
Oculocephalic response - eyes should stay in place, moving opposite to the rotation of the head
COWS as well
Cervical spine fracture
172
What is skew deviation of the eyes indicative of?
Brainstem lesion
173
What is ocular bobbing indicative of?
Very severe head injury with pontine damage
