Clinical Medicine - Neurology

Lesion

area of tissue which has been damaged by disease or injury

Localization

process of determining where the lesion exists through H&P and diagnostics

Type localization

what dysfunction is present? - focal, multifocal, diffuse, specific system, or mixed

Grey matter

majority of neuronal somas

extends from brain (outermost/cortex) to the cord (central horn-like structure)

Cord grey matter sections

anterior grey column

posterior grey column

lateral gray column

Grey matter throughout the CNS allows

control movement, memory, and emotion

White matter

myelinated fiber tracts

in brain - connects various parts of cortex for processing and integration

in cord - sensory and motor pathways to and from brain

In skeletal muscle innervation, release of _____ by axon terminal causes transmission of impulse

acetylcholine

Parasympathetic vs sympathetic neurotransmitter

parasympathetic - ACh

sympathetic - NorEpi

Dura mater

outermost, dense fibrous membrane

provides protection against acceleration/deceleration via reflections: falx cerebri, tentorium cerebelli, falx cerebelli

supports venous sinuses

Arachnoid mater

delicate impermeable membrane

separated from dura by subdural space and from pia by subarachnoid space

all cerebral arteries and veins as well as cranial nerves in subarachnoid space with CSF

Pia mater

vascular membrane

most closely adherent to brain and spinal cord

Brain stem

compromised of the medulla oblangata, the pons, and midbrain

reflex centers for respiration, CV, and control of consciousness

contains important nuclei of CN 3-12

contains vomiting and swallowing centers

Cerebellum

timing of motor activities and rapid, smooth progression of movement

coordinates posture, balance, and speech

Basal ganglia

assists in control of complex movements

Diencephalon

thalamus and hypothalamus

Cerebrum

frontal, parietal, temporal, and occipital lobes

Cerebral cortex - frontal

complex problem solving, personality, judgement, and voluntary movement

Broca's area - motor speech

Cerebral cortex - parietal

perception of sensation at primary somesthetic area, located on postfrontal gyrus

Cerebral cortex - occipital

primary visual area

Cerebral cortex - temporal

primary auditory area

Wernicke's area - sensory speech/understanding of written and spoken language

"Spino-" tract

sensory tract

"-spinal" tract

motor tract

3 main sensory systems in spinal cord

pain-temperature

proprioception-stereognosis

light touch

Pain-temperature pathway

enters cord and crosses over immediately

spinothalamic

Proprioception-stereognosis pathway

initially remains on same side then crosses over at brainstem

spinocerebellar

Light touch pathway

combines features of 2 previous tracts

some crosses at lower levels and some at brain stem

med lemniscus

spinothalamic

Motor pathway

down through brainstem and crosses over at junction with cord

Upper motor neuron lesions

weakness

increased reflexes

increased tone

no atrophy or fasciculations

Lower motor neuron lesions

weakness

atrophy

fasciculations

decreased reflexes

decreased tone

Reflex arc

Bell Palsy

sudden onset of facial paresis caused by an inflammatory response involving the facial nerve

idiopathic

MC in DM and pregnancy

Bell Palsy S&S

abrupt facial paralysis that gradually worsens

ear pain on affected side

numbness

difficulty eating

excessive tearing

difficulty closing ipsilateral eye

poor fine facial movements - inability to wrinkle forehead

Bell Palsy vs Stroke

Bell Palsy management

further workup unless suspicion for herpes zoster, Lyme, HIV, or tumor

Bell Palsy treatment goals

improve facial nerve function

prevent complications like corneal damage

minimize long-term sequelae

Bell Palsy treatment

self-limiting and benign with full resolution in up to 6 months

if within 72 hrs: corticosteroids - high dose prednisone

antiviral therapy - acyclovir or valacyclovir

eye drops, patches, moisture chambers

facial exercises

Trigeminal neuralgia

MCC of neuralgic pain in face

unilateral pain involving 2nd, 3rd, or both branches

Trigeminal neuralgia S&S

sudden onset, severe facial pain lasting seconds

sharp, stabbing, or burning

may be precipitated by touch or movement

daily attacks

Trigeminal neuralgia diagnostics

MRI w/ and w/o

Trigeminal neuralgia pathophysiology

ecstatic vascular loop of superior cerebellar artery that compresses and demyelinates the trigeminal nerve

Trigeminal neuralgia treatment

carbamazepine or oxcarbazepine

phenytoin, gabapentin, or topiramate

topical anesthetics

if refractory - injections or surgery

Herpes zoster

reactivation of dormant varicella zoster secondary to immune response

painful vesicular rash in single dermatome

Herpes zoster S&S

stereotypical rash preceded by 2-3 days of burning, tingling, or pain in dermatomal distribution

may be followed by fatigue, malaise, low grade fever, and HA

if pain persists past 1 month --> post herpetic neuralgia

Herpes zoster opthalmicus

distribution of CNV and may involve cornea

Herpes zoster oticus

aka Ramsay Hunt syndrome

involves facial nerve causing facial paralysis or severe ear pain

Herpes zoster diagnostics

Tzanck smear or clinical dx

Herpes zoster treatment

antiviral therapy with initiation within 72 hrs - acyclovir, valacyclovir, or famciclovir

analgesic - NSAID, narcotic, anticonvulsants (gabapentin or pregabalin), TCAs (amitriptyline or nortriptyline)

topical analgesics - lidocaine or capsaicin

prevent secondary bacterial infections

Spongiform encephalopathy

group of progressive, fatal neurodegenerative disorders characterized by spongiform changes in brain tissue triggered by prions

Creutzfeldt-Jakob Disease (CJD)

Variant CJD (vCJD or BSE)

Gerstmann-Straussler-Scheinker Syndrome (GSS)

Fatal Familial Insomnia (FFI)

Kuru

most often diagnosed post-mortem

Spongiform encephalopathy etiology

sporadic, genetic, or acquired

Spongiform encephalopathy S&S

rapidly progressive dementia

myoclonus

visual disturbances

cerebellar dysfunction (ataxia)

behavior changes

Spongiform encephalopathy diagnosis

clinical

MRI - hyperintense signals in putamen and caudate nucleus

definitive - biopsy or autopsy

Spongiform encephalopathy treatment

supportive

death typically within 1 year

Hashimoto encephalopathy

rare, potentially treatable autoimmune encephalopathy associated with Hashimoto's thyroiditis

linked to anti-thyroid antibodies (anti-TPO and anti-thyroglobulin)

Hashimoto encephalopathy S&S

cognitive impairment

seizures

myoclonus

psychosis

ataxia

stroke-like episodes

Hashimoto encephalopathy diagnostics

elevated anti-TPO and anti-Tg

normal-mildly abnormal thyroid function tests

r/o other causes (infections, metabolic disturbances, and neoplasms)

response to corticosteroid treatment supports diagnosis

Hashimoto encephalopathy - diagnostic criteria

need all 6:

1. encephalopathy with seizures, myoclonus, hallucinations, or stroke-like episodes

2. subclinical or mild overt thyroid disease

3. brain MRI normal or non-specific

4. presence of serum thyroid antibodies

5. absence of well-characterized neuronal antibodies in serum and CSF

6. reasonable exclusion of alternative cases

Hashimoto encephalopathy treatment

corticosteroids - high dose prednisone or IV methylprednisolone

alternative immunosuppressive therapies - azathioprine, mycophenolate mofetil, or rituximab if refractory

supportive care

Wernicke encephalopathy

acute neuropsychiatric syndrome resulting from thiamine (B12) deficiency

Wernicke encephalopathy etiology

MCC - alcoholism

malnutrition or malabsorption

hyperemesis gravidarum

prolonged IV feeds w/o B12 supplements

Wernicke encephalopathy S&S

triad - ocular abnormalities, gait ataxia, mental status changes

hypotension, hypothermia, peripheral neuropathy

Wernicke encephalopathy diagnostics

H&P

low serum thiamine levels

MRI with bilateral lesions in thalami, mammillary bodies, periaqueductal area

Wernicke encephalopathy treatment

high dose thiamine IV

then oral thiamine supplementation

Wernicke encephalopathy progression

Korsakoff syndrome - amnesia and confabulation

Hepatic encephalopathy

neuropsychiatric syndrome caused by liver dysfunction leading to accumulation of neurotoxins in blood

acute liver failure, chronic liver disease

precipitating factors - GI bleeding, infection, high protein intake, dehydration, electrolyte imbalances, certain meds

Hepatic encephalopathy S&S

cognitive changes

neuromuscular abnormalities - asterixis, hyperreflexia, rigidity

behavioral changes

stupor or coma

Hepatic encephalopathy diagnostics

elevated blood ammonia levels

LFTs

exclusion of other AMS causes - intracranial or metabolic issues

Hepatic encephalopathy treatment

treat underlying cause

lactulose

rifaximin

dietary management

Questions to ask with headaches

onset

location

precipitating events

progression

provocative

quality

radiation

severity

timing

Headache classification

primary - no structural or metabolic etiology

secondary - related to underlying condition

Headaches requiring immediate intervention

vascular

infections

mass lesions

pre-eclampsia

CO poisoning

Headache imaging indications

"worst headache ever"

sudden pattern change

over 50

positional

seizure

fever

head injury

pulsatile sounds

focal signs

history of CA or HIV

related to exercise, sex, coughing, sneezing, urination, or defecation

refractory

severe patient anxiety

Subarachnoid hemorrhage

sentinel headache

MCC - trauma

if spontaneous - most often 2nd to aneurysm rupture

Subarachnoid hemorrhage S&S

"worst headache of my life"

NV

meningismus

alteration of consciousness

focal deficits often absent

Subarachnoid hemorrhage workup

non-contrast CT stat!

LP if scan negative or ambiguous

cerebral angiography - if negative CTA after 2 weeks

Headache types

sinus - behind forehead and/or cheekbones

cluster - in and around 1 eye

tension - hat band pain

migraine - pain, nausea, visual changes

Tension headaches

MC type of headache

hat band formation but can also be generalized

no nausea or vomiting

Tension headaches management

regulate sleep and meals

exercise

stress management

biofeedback and CBT

acetaminophen, ibuprofen, naproxen, ASA, caffeine

if chronic - TCA or anticonvulsants

Episodic tension-type headache diagnostic criteria

Migraine headaches

at least 5 attacks lasting 4-72 hrs

at least 2: unilateral, pulsating, mod-sev, aggravation by walking

at least 1: NV, photophobia, and phonophobia

w or w/o aura

focal deficits may occur - disequilibrium, paresthesia, aphasia

Basilar artery migraine

blindness or binocular visual disturbances

dysarthria, tinnitus, perioral and distal paresthesia precede HA

occipital HA

Ophthalmoplegic migraine

periorbital pain and diplopia

4th or 6th CN palsy

may outlast HA by weeks

Migraine equivalent

neuro or somatic complains occurring in isolation

"migraine w/o HA"

Migraine treatment

avoidance of triggers

abortive therapy

prophylactic therapy

Precipitating factors of migraines

stress

foods

+/- sleep

light

noise

menstrual cycle

OCP

Precipitating factors of cluster HAs

alcohol

stress

light

foods

Migraine - abortive treatment

OTC analgesics

Rx NSAIDs - diclofenac, etodolac

ergotamines - DHE (spray or injection) or cafergot PO

Triptans - first line

CGRP inhibitors

monoclonal antibodies - Aimovig, Ajovy, Emgality

Gepants - Ubrelvy or Nurtec

Ergotamines are contraindicated in

vascular disease, NV, diarrhea

Triptans are contraindicated in

vascular disease or complex migraine

Triptans

sumatriptan

Imitrex

Maxalt

Relpax

Zomig

Amerge

Axert

Frova

Treximet

Triptans in pregnancy

pregnancy category C

Migraine prophylaxis indications

3 or more episodes per month

significant impact on daily activity

abortive medications ineffective, contraindicated, overused, or giving adverse effects

patient preference

Migraine prophylaxis meds

beta blockers

CCBs

anti-depressants (SSRIs/Tricyclics)

seizure meds (topamax, depakote, neurontin, zonisamide)

Botox injections

Cefaly headband

Cluster headaches

short, severe, unilateral occurring in clusters (1-many/day for 2 weeks to months)

episodes last 15 min - 3 hrs

extended pain free intervals

periorbital

lacrimation

rhinorrhea or nasal congestion

eyelid swelling

fatigue

Cluster headache treatment

oxygen via non-rebreather

sumatriptan injection

zolmitriptan nasal spray

viscous lidocaine intranasally

DHE IM

Verapamil - first line for preventative

Occipital neuralgia

chronic pain in upper neck, posterior aspect of head, and/or retroorbital pain

Occipital neuralgia etiology

trauma to back of head

compression of occipital nerves

inflammation or irritation of occipital nerves

medical conditions

muscle tension and strain

poor posture

Occipital neuralgia S&S

sharp, shooting, or electric-shock like pain at base of skull radiating to scalp

pain behind eyes

photophobia

scalp tenderness

Occipital neuralgia diagnostics

H&P

diagnostic nerve blocks

Occipital neuralgia treatment

rest, heat, PT, NSAIDs

muscle relaxants, anticonvulsants, antidepressants

nerve blocks and steroid injections

Botox

surgical decompression

neurostimulation