Neurology Flashcards
Li-Fraumeni syndrome
TP53 Mutation
Autosomal dominant
Caused by inactivating mutation in corresponding tumor suppressor gene
Deletion of remaining normal allele (second hit) leads to loss of heterozygosity & malignant transformation
Sarcomas, Breast cancer, Brain tumors, Adrenocortical carcinoma, Leukemia
Trigeminal Neuralgia
Sudden severe pain in the distribution of CN-V (particularly V1 &V2)
Pain is like stabbing or electric shock
triggered by chewing, brushing, shaving, washing the effected area etc.
Carbamazepine is DOC
Horners Syndrome
Ipsilateral
Ptosis, Miosis, Anhydrosis
MCA Occlusion
- Contralateral Hemiparesis
- Contralateral Hemisensory loss of face and upper limb, lower limb usually preserved,
- If in dominant hemisphere (usually left) aphasia may also occur.
PCA Occlusion
Contralateral Hemianopia with Macular sparing (contralateral supply from MCA)
AICA Occlusion
Causes Lateral Pontine Syndrome
Ipsilateral loss of pain or temperature in the face (trigeminal nucleus),
Ipsilateral facial weakness (facial nucleus),
Ipsilateral hearing impairment (cochlear nucleus),
Contralateral loss of pain and temperature in the trunk and extremities (lateral spinothalamic tract),
Cerebellar dysfunction (eg, ataxia, dysmetria).
Anterior communicating Artery Aneurysms
compress the central optic chiasm, causing bitemporal hemianopia
Posterior communicating Artery Aneurysm
compresses the oculomotor nerve,
Ipsilateral mydriasis, Ptosis,
“down and out” eye deviation
ACA Occlusion
Contralateral motor & sensory deficits,
lower limb affected more than upper limb
Bilateral occlusion causes significant behavioral symptoms (eg, abulia), primitive reflexes (eg, Moro, grasp), and urinary incontinence due to damage of the prefrontal cortex.
Basilar Artery Occlusion
damages base of pons, contains the corticospinal and corticobulbar tracts, and the paramedian tegmentum.
Patients typically have Quadriplegia, Bulbar dysfunction (eg, facial weakness, dysarthria), and Oculomotor deficits (eg, horizontal gaze palsy).
Neurofibromatosis type I
- Café-au-lait spots,
- Lisch nodules (iris hamartoma),
- cutaneous neurofibromas,
- pheochromocytomas,
- optic gliomas
Neurofibromatosis type II
Bilateral vestibular schwannomas
Guillain-Barré syndrome
(acute inflammatory demyelinating polyneuropathy)
Rapidly progressive limb weakness that ascends following GI/upper respiratory infection
Multiple sclerosis
Nystagmus, intention tremor, scanning speech, bilateral internuclear ophthalmoplegia, optic neuritis
Optic Neuritis: pain with eye movement, intermittently decr vision, swelling of optic disc.
May worsen with heat exposure
Demylinating plaques commonly seen as hyperintense lesion on MRI of brain and spinal cord.
Plaques in the white matter.
Increase IgG in the CSF.
Normal pressure hydrocephalus
- Urinary incontinence,
- Gait ataxia,
- Cognitive dysfunction
Huntington disease
(autosomal dominant CAG repeat expansion)
“ C D C “
Chorea, Dementia, Caudate degeneration
Enlargement of Lateral Ventricles is seen in the brain.
Parkinson disease
(loss of dopaminergic neurons in substantia nigra pars compacta)
Resting tremor, rigidity, akinesia, postural instability,
shuffling gait, micrographia
“ T R A P “
T = Tremor
R = Rigidity (Cogwheel rigidity)
A = Akinesia
P = Postural instability
Lewy bodies seen on histology which are made up of Alpha-synuclien.
Depigmentation of substania niagra can be seen on autopsy.
Klüver-Bucy syndrome
(bilateral amygdala lesion)
Hyperphagia, hypersexuality, hyperorality
Wernicke encephalopathy
Caused by Vitamin-B1 (Thiamine) deficiency in alcoholics
Confusion, Ophthalmoplegia/Nystagmus, Ataxia (add confabulation/memory loss for Korsakoff syndrome)
Damage to Mamilliary bodies.
Cri-du-chat (cry of the cat) syndrome
Microcephaly, high-pitched cry, intellectual disability
Toxoplasmosis
Multiple ring enhanced lesions around pareital lobe, from cat feces
Congenital CMV
spastic diplegia of legs,
hepatosplenomegaly,
blinding,
Central calcifications
Hyperammonemia
flapping tremor (asterixis), slurring
of speech, somnolence, vomiting, cerebral
edema, blurring of vision.
CNS toxicity
may involve GABA, α-ketoglutarate, TCA
cycle inhibition, and cerebral edema due to
glutamine-induced osmotic shifts.
Diabetic Mononeuropathy
Hx of Diabetes
Microvascular damage to tissues (i.e Nerves)
Can cause Abducens nerve palsy present as
Esotropia
Unilateral adduction deficit
Diplopia in horizontal gaze
Waterhouse-Fredriechsen Syndrome
Is caused by gram –ive diplococcus
Niesseria Meningitis
Meningitis, Sepsis, DIC, Bilateral adrenal hemorrhage.
Adrenal insufficiency presents as:
Hypotension, Hyperkalemia, Hyponatremia and Hypoglycemia due to deficiency of aldosterone and glucocorticoids.
Bells Palsy
Isolated facial nerve palsy (CN-VII)
Typically secondary to HSV reactivation
Complete ipsilateral facial weakness involving forehead,
1- Loss of forehead or brow movements.
2- Inability to close eyes & drooping of eyelids.
3- Loss of nasolablial folds & drooping lower lip
Taste and hearing abnormalities, (Loss of taste ant 2/3 of tounge & Hyperacusis)
Decreased tear production
Loss of sensation from portions of pinna to EAC
Occulomotor Nerve Palsy
Occulomotor nerve innervates motor innervation to levator palpebrae superioris, Superior, Medial, Inferior rectus muscle and inferior oblique muscle
Deficit presents as:
Ptosis, Exotropia, Hypotropia
Abducens Nerve Palsy
Abducens Nerve exits brainstem ventrally to pontomedullary junction.
Innervates the lateral rectus muscle of eye
May result from microvascular ischemia
Presents as;
Binocular horizontal diplopia
Ipsilateral abduction deficit of effected eye.
Myotonic Dystrophy
Expansion of Trinucleotide repeat CTG
Type-1 : DMPK gene
Type-2 : CNBP gene
Characterized by:
Ptosis, Facial muscle atropy, Muscles weakness, Myotonia, Cataracts, Frontal balding, Cardiac arythmias, Hypogonadism.
More frequently affected muscles are facial muscles, sternlcloidomastoid, distal forearm, instrinsic hand and ankle dorsiflexion.
It is assosiated with presence of ring fibers and central nuclei on muscle biopsy.
Anticholinestrase poisoning
Aka Organophosphate poisoning
Irreversible inhibition of acetylcholinesterase
Symptoms include:
Vomitting, Diarrhea, Diaphoresis, Urination, Lacrimation, Salivation, Bronchorrea, Bronchospasm, Bradycardia, Siezures, Muscle weakness
Responsible toxins are:
Parathoin , Fenthoin , Malathoin.
Tx:
Atropine : antagonizes muscranic receptors.
Pralidoxime : Regenerate function AchE.
Tourrette syndrome
Motor and vocal tics that presist for > 1 year.
Tx: Fluphenazine, Resperidone
Rett Syndrome
Only in girls
Decreased head growth
Hand wringing
Lose motor skills (Normal until 5 months of age)
Malignant Hyperthermia
Widespread muscle rigidity after administration of inhalation anesthetics and/or succinylcholine to genetically susceptible individuals.
Genetic mutation in Rayanodine receptors
Unregulated sarcoplasmic Ca+2 release —> sustained muscle contraction
Symptoms:
- Masseter muscle spasm
- Widespread muscle rigidity
- Hypercarbia
- Rhabdomyolysis —> Hyperkalemia & ARF.
- Hyperthermia (late manifestation)
Dantrolene is used for treatment it directly inhibits intracellular Ca+2 release from abnormal ryanodine receptors (RYR1).
Lewy-Body Dementia
Parkinsonism + visual hallucinations + cognitive decline.
Sturge-weber syndrome
- Cutaneous Angioma over head & neck (Portwine stain).
- Focal/ generalized siezures.
- Hemiparesis.
- Intellectual disability.
Kids go on to develop Glaucoma.
Tuberous Sclerosis
AD mutation in Hamartin gene (chromosome 9) or Tuberin gene (chromosome 16).
- Hamartomas (can present anywhere in body).
- Siezures.
- Psychomotor delay.
- Intellectual disability.
- Adenoma sebaceum.
- Ash-leaf spot & Shagreen patches.
Also assosiated with kidney tumors known as Renal angiomyolipomas and heart tumor i.e Cardiac rhabdomyoma.
Chediak-Higashi syndrome
LYST gene : Defect in microtubule function.
Presents as;
“ C A I N “ C = Coagulopathy. A = Albinism. I = Infections. N = Neuropathy.
Neonatal Herpes
- Caused by HSV-2 infection
- Characterized by:
> Vesicular Rash
> Encephalitis ( Siezures, CN palsies, Lethargy) - Typically acquired during delivery.
- Usually occurs 2 weeks after birth no symptoms at birth.
What is pituitary apoplexy?
Acute pituitary hemorrhage.
It usually occurs in the setting of a preexisting pituitary adenoma.
Symptoms include:
1. Severe headache
2. Bitemporal hemianopsia (due to compression of the optic chiasm)
3. Ophthalmoplegia (due to compression of the oculomotor nerve [CNIII])
Neuroblastoma
- Young child with large abdominal mass.
- Urine shows elevated catecholamine metabolites.
- Biopsy shows small, round, blue tumor cells.
- This tumor is of neural crest cell origin.
Waterhouse-Friderichsen syndrome is a potential complication of?
Meningococcemia.
It is characterized by bilateral hemorrhagic infarction of adrenal glands, resulting in acute adrenal insufficiency (eg, worsening shock).
Parkinson disease (TRAP mnemonic)
- Tremor
- Rigidity
- Akinesia/bradykinesia
- Postural instability (late finding)
Amyotrophic lateral sclerosis
UMN: degeneration & atrophy of lateral corticospinal tracts, precentral gyrus
LMN: degeneration of anterior horn (thin anterior roots) & cranial nerve motor nuclei
Muscle: denervation atrophy (angular fibers with crowded nuclei)
Clinical manifestations:
UMN symptoms: spasticity, hyperreflexia, pathologic reflexes
LMN symptoms: muscle weakness, atrophy, fasciculation
Treatment
Riluzole: reduces glutamate-induced excitotoxicity & improves survival
Localizing signs: Brain Lesions
- Eyes will look (toward) a stroke and (away from) a seizure.
- Uvula will deviate (away from) the lesion.
- Jaw will deviate (toward) the lesion.
- Shoulder will droop (ipsilateral) to the lesion.
- Tongue will deviate (toward) the lesion.
What is the triad of Wernicke encephalopathy?
What structure is affected?
- Ataxia, ophthalmoplegia (Nystagmus), and encephalopathy (Confusion).
- Mamillary body are affected.
- Cause: Thiamine deficiency (Alcoholics)
Gerstmann syndrome
- Agraphia (inability to write)
- Acalculia (inability to solve mathematical calculations)
- Finger agnosia (inability to identify individual fingers on the hand)
- Left-right disorientation
Myasthenia gravis
Autoantibodies against nicotinic acetylcholine receptors on the (post) synaptic membrane of the neuromuscular junction
Associated with Thymoma
Lambert-Eaton syndrome
autoantibodies against voltage-gated calcium channels on the (pre) synaptic membrane of the neuromuscular junction
Associated with Small cell lung cancer (SCLC)
Absence Seizures
Brief staring spell momentary loss of awareness, abrupt return to full conciousness.
3Hz spike wave of EEG
Rx: Ethuxomide (Inhibit T-type Ca+2 channels in thalamic neurons)
Ménière disease
episodic vertigo, sensorineural hearing loss, and tinnitus with aural fullness.
increased volume and pressure of endolymph in the vestibular apparatus.
Narcolepsy
- Excessive day time sleepiness
- Cataplexy (Episodic loss of motor tone, triggered by emotion.
- Sleep Paralysis (Inablility to move on awakening)
- Hypnagogic or Hypnopompic hallucinations.
- Caused by lack of two neuropeptides:
- Hypocretin-1 (Orexin -A)
- Hypocretin -2 (Orexin-B)
Increase in WBC in CSF
Meningitis
- Normal CSF may have upto 25 WBC in age < 1 month
- In age > 1 month Only upto 3 WBC is normal
Normal Pressure Hydrocephalus
Wet , Wacky , Wobbely
Traid of:
- Dementia
- Urge Incontinence
- Ataxia
Meningioma
- Most common intra-cranial tumor
- Displaces the brian
- Histology shows “ Psammoma Bodies “
Lateral Pontine Syndrome
- AICA Occlusion
- CN 7- Ipsilateral Facial Paralysis (Bells Palsy)
- CN 8- Hearing loss
Lateral Medullary Syndrome
(Wallenberg Syndrome)
- Occlusion of PICA
- Cerebellar Puduncle- Ipsilateral limb ataxia
- Descending Hypothalamics- Ipsilateral Horner Syn
- Nucleus Ambiguus: Dysphagia
Medial Medullary Syndrome
- Occlusion of Vertibral artery
- Pyramid- Contralateral spastic hemiparesis
- CN 12- Tounge deviates towards the lesion
Median Midbrain Syndrome
(Weber)
- Occlusion of PCA
- Corticospinal tract- Contralateral spastic hemiparesis in upper limb
- Corticobulbar tract- contralateral side of Lower face effected
- CN 3- Eye down & Out
Cranial Nerves Location
- Midbrain - CN 3, 4
- Pons - CN 5 , 6 , 7 , 8
- Medulla - CN 9 , 10 , 11 , 12
Spinal Cord Lesion
- Pain & Temperature deficit is on the opposite side (contralateral) to all other deficits in the body.
- Level of lesion is 2 dermatome above where loss of pain & temp sensation begins and on the opposite side.
CNS Lesion
- UMN signs on one side of body
(I.e. Hyperreflexia, Babinski + , Spasticity, Clonus) - Then the lesion is on the opposite side of brain
- Use location of cranial nerves to locate the lesion:
- Midbrain - CN 3, 4
- Pons - CN 5 , 6 , 7 , 8
- Medulla - CN 9 , 10 , 11 , 12
Dorsal Coloumns
Responsible for:
- Vibratory sensation
- Two- Point discrimination
- Position sense
- Concious Proprioception
Dorsal coloumn pathologies are:
- Syphilis
- Vit- B12 deficiency
- Brown- Sequard
Pseudo Motor Cerebri
- Idiopathic intracranial hypertension, Elevated intracranial pressure
- Absence of ventricular enlargement on imaging
- This classically presents in young, obese women presents with:
- Headache
- Papilledema
- Vision loss due to Optic Neuropathy
