Nervous System - Diseases Flashcards
Multiple Sclerosis
Autoimmune demyelinating disease of the CNS, most often affecting women in their 20s and 30s with a relapse-remitting course
Presents with optic neuritis (sudden loss of vision, Markus-Gunn pupil), hemiparesis/hemisensory defects, bladder/bowel incontinence, ‘scanning speech’, intention tremor
Treatment: Beta-interferon, immunosuppression, Natalizumab
Major Depressive Disorder
Characterized by at least one major depressive episode lasting 6+ months, characterized by patient-reported depressed mood/anhedonia + SIGECAPS (Sleep disturbance, loss of interest, guilt, energy loss, poor concentration, changes in appetite/weight, psychomotor retardation/agitation, suicidal ideation)
Bipolar Disorder I
Characterized by the presence of at least one manic episode lasting 1 week or requiring hospitalization, characterized by DIGFAST: Distractability, Irritability/Irresponsibility, Grandiosity, Flight of Ideas, Agitation/increased activity, Decreased need for Sleep, Talkativity/Pressured Speech
Acute mania is treated with atypical psychotics
Lithium prevents and reduces severity of manic episodes
Bipolar Disorder II
Characterized by the presence of at least one hypomanic episode and one depressive episode
Hypomania presents similarly to mania (DIGFAST) but less severe and with symptoms lasting at least 4 days and not requiring hospitalization
Schizoid Personality Disorder
Characterized by voluntary social withdrawal and limited emotional expression; content in social isolation (vs. avoidant)
Schizotypal Personality Disorder
Characterized by eccentric appearance, odd or magical thinking, and interpersonal awkwardness
Schizophrenia
Characterized by psychosis (hallucinations, delusions, disturbed thoughts/behavior) lasting at least 6 months; may also present with disorganized speech/behavior or negative symptoms (flat affect, social withdrawal)
Treated with anti-psychotics and atypical anti-psychotics
Schizophreniform Disorder - same diagnostic criteria but symptoms lat 1-6 months
Schizoaffective Disorder
Characterized by psychotic features of schizophrenia + major mood disorder (Bipolar, Major Depression)
Alzheimer Disease
90% Sporadic, 10% Familial; early onset familial cases associated with mutations in APP (Chr 21), Presenelin-1 (Chr 14), and Presenelin-2 (Chr 1); late onset associated with ApoE4 (Chr 19) whereas ApoE2 (Chr 19) is protective
Findings: Widespread cortical atrophy, B-amyloid plaques (extracellular), neurofibrillary tangles (intracellular tau protein accumulation), decreased ACh
Lewy Body Dementia
Findings: Lewy Bodies (a-synuclein inclusions)
Presents as dementia, visual hallucinations, and Parkinsonism
Parkinson Disease
Degenerative disorder of the CNS caused by accumulation of Lewy Bodies (a-synuclein) in the substantia nigra; characterized by decreased dopamine and increased ACh
Presents with resting tremor, cogwheel rigidity, bradykinesia, postural instability, and shuffling gait
Treatment: L-DOPA/Carbidopa, Amantidine, Selegiline, Entacapone/Tolcapone, Benzotropine
Communicating Hydrocephalus
Decreased CSF reabsorption by arachnoid granulations, i.e. caused by arachnoid scarring post-meningitis
Causes increased intracranial pressure, papilledema, and herniation
Normal Pressure Hydrocephalus
Communicating hydrocephalus causing enlargement of the ventricles which distort the corona radiata
Presents with triad of urinary incontinence, ataxia, and cognitive decline
Non-communicating Hydrocephalus
Caused by structural blockage of CSF circulation within the ventricular system
Erb-Duchenne (Waiter’s Tip) Palsy
Caused by damage to the C5 and C6 nerve roots during delivery; damages abductors, flexors, and supinators of the upper arm
Arm hangs by side (abducted) with forearm pronated and wrist flexed
Central Pontine Myelinolysis
Osmotic demyelination of the corticobulbar and corticospinal tracts caused by over-correction of hyponatremia with hypertonic saline
Presents with dysarthria, dysphagia, and rapid paralysis
MRI shows abnormally increased signal in pons
Lateral Medullary Syndrome (Wallenberg Syndrome)
Caused by vascular disruption of the PICA, which supplies the lateral medulla
Presents with:
Vomiting and vertigo (vestibular nuclei)
Loss of pain and temperature from contralateral body (lateral spinothalamic tract)
Loss of pain and temperature from ipsilateral face (spinal trigeminal nucleus)
Dysphagia and hoarseness (nucleus ambiguus)
Ipsilateral Horner Syndrome (descending sympathetics)
Horner Syndrome
Caused by disruption of the descending sympathetic fibers above the level of T1; disrupts innervation of facial sweat glands, pupillary dilator, and smooth muscle of the eyelid
Presents with: Unilateral ptosis, anhidrosis, miosis
Lithium Toxicity
Presents with memory impairment, confusion, nausea/vomiting, dysarthria lethargy, coarse hand tremor; progresses to ataxia, hyperreflexia, seizures, and coma
Also associated with hypothyroidism and nephrogenic diabetes insipidus
Viral Meningitis
Most often caused by enteroviruses (in kids) or HSV (in adults)
CSF findings: Elevated WBCs (mostly lymphocytes), slightly elevated or normal protein, normal glucose, normal opening pressure
Viral Encephalitis
HSV-1 is the most common cause
Presents with AMS, personality changes
CSF Findings: Bloody CSF, elevated WBC (mostly lymphocytes), normal or slightly elevated protein, normal glucose
Imaging shows temporal lobe involvement
HIV-associated dementia
Most common direct CNS complication of HIV, occurring late in the course of disease
Early symptoms - depression, apathetic withdrawal; progresses to global cerebral atrophy, motor deficits
Findings: Elevated protein and IgG in CSF; MRI shows non-enhancing, poorly demarcated areas of increased signal on T2 in the deep white matter
Locked-In Syndrome
Caused by occlusion or hemorrhage of the Basilar a. which supplies the pons, medulla, and lower midbrain including the corticospinal and corticobulbar tracts
Presents as quadriplegia and loss of all facial, mouth, and tongue movements
Oculomotor and Trochlear nerves are spared with preserved blinking and up-gaze
Cluster A Personality Disorder - Characteristics and Conditions (3)
Odd or eccentric thinking/behavior with inability to form meaningful social relationships
Paranoid
Schizoid
Schizotypal
Paranoid Personality Disorder
Cluster A
Characterized by pervasive distrust and suspicion
Schizoid Personality Disorder
Cluster A
Characterized by voluntary social withdrawal - individual is content with social isolation (vs. avoidant); limited emotional expression
Schizotypal Personality Disorder
Cluster A
Characterized by eccentric appearance, odd/magical thinking, and interpersonal awkwardness
Cluster B Personality Disorders - Characteristics & Conditions (4)
Dramatic, overly emotional, and erratic; genetic association with mood disorders and substance abuse
Antisocial
Borderline
Histrionic
Narcissitic
Antisocial Personality Disorder
Cluster B
Characterized by disregard for and violation of others’ rights, criminality, and impulsivity; males > females
Diagnosis requires age > 18 with hx of conduct disorder < 15
Diagnosed as conduct disorder in patients < 18
Borderline Personality Disorder
Cluster B
Characterized by unstable moods and interpersonal relationships, impulsivity, self-mutilation; females > males
Major coping mechanism is “splitting” - a tendency to view others as ALL good or bad
Histrionic Personality Disorder
Cluster B
Characterized by excessive emotionality and excitability, attention seeking, sexual provacation, and excessive concern with appearance
Narcissistic Personality Disorder
Cluster B
Characterized by grandiosity, sense of entitlement, lack of empathy; require excessive praise and often respond to criticism with rage
Cluster C Personality Disorders - Characteristics & Conditions (3)
Anxious and fearful
Genetic association with anxiety disorders
Avoidant Personality Disorder
Cluster C
Hypersensitive to rejection, socially inhibited with feelings of inadequacy
Desires relationships with others (vs. Schizoid)
Dependent Personality Disorder
Cluster C
Submissive, clinging, with low self confidence and excessive need to be taken care of
Obsessive Compulsive Personality Disorder
Cluster C
Excessive preoccupation with perfection, order, and control
Ego-syntonic (vs. OCD) - behavior and thoughts are consistent with one’s own beliefs and attitudes
Epidural hematoma
Most commonly caused by rupture of the middle meningeal artery secondary to temporal trauma
Rapid expansion of hematoma under arterial pressure causes trans-tentorial herniation (CNIII Palsy); presents with lucid interval
CT shows hyper-dense, “lens-shaped” accumulation of blood which crosses the falx and tentorium but does not cross suture lines
Subdural hematoma
Caused by rupture of the bridging veins leading to gradual development of hematoma
Increased risk in elderly, alcoholics, blunt trauma, shaken babies
CT shows hyperdense, “crescent-shaped” hematoma which crosses suture lines but does NOT cross falx or tentorium; may cause mid-line shift (sub-falcine herniation)
Subarachnoid hemorrhage
Caused by rupture of aneurysm; increased risk in connective tissue diseases (Marfan’s, Ehler’s Danlos, AVM)
Presents with “worst headache of my life”
CT shows hyperdense accumulation of blood in the sulci and/or ventricles; + blood in spinal tap
Intraparenchymal (hypertensive) hemorrhage
Most commonly occurs as a result of systemic hypertension, but can also be seen in amyloid angiopathy, vasculitis, neoplasm
Most commonly affects the basal ganglia and/or internal capsule
Subacute sclerosing panencephalitis (SSPE)
Sequelae of measles (Rubeola) virus, occurring 7-10 years after infection due to progressive demyelination of the CNS
Presents in 4 stages:
- Personality changes
- Myoclonus
- Worsening dementia
- Decorticate posturing, death
Pineoblastoma
Arise from the pineal gland, located between the thalamic bodies and responsible for melatonin secretion and regulation of sleep/wake cycles
Presents as excessive sleepiness and/or vivid dreams; most commonly in patients < 20 years old
Radial Neuropathy
Damage to the radial nerve
May occur as a result of mid-shaft fracture of the humerus (where radial n. sits within the spiral groove) or compression of the axilla (crutches, “Saturday Night Palsy”)
Radial n. innervates the brachioradialis, extensors of the wrist and fingers, supinator, and triceps (“BEST”)
Presents with loss of extension at elbow, wrist, and fingers (‘wrist drop’), diminished grip strength, and loss of sensation over the posterior arm/forearm and dorsal hand
Craniopharyngioma
Most common supra-tentoral neoplasm in children; accounts for 80-90% of pituitary area lesions in kids
Most children present with endocrine dysfunction: GH deficiency, gonaotropin deficiency, ACTH deficiency, TSH deficiency; less commonly hyperprolactinemia or central DI due to pituitary stalk dysfunction
Dx: Large, well-circumscribed, suprasellar mass +/- calcifications
Tricyclic Antidepressant Overdose - Clinical Syndrome
“3 Cs” - Coma, convulsions, cardiotoxicity
Presentation varies but may include hypotension, anticholinergic effects, respiratory depression, hyperpyrexia, cardiac conduction defects and life-threatening arrhythmias, seizures
Treated with bicarbonate; alkalinization of plasma increases bidning of TCA to plasma proteins, reducing the amount of TCA bound to myocardial calcium channels and thereby stabilizing the myocardium. Improved perfusion resolves the metabolic acidosis
Cluster Headaches
Repetitive, unilateral, brief (15 minutes - 3 hour) headaches characterized by excruciating periorbital pain with lacrimation and rhinorrhea; may induce Horner syndrome
Treatment: Inhaled oxygen, Sumatriptan
Tension headaches
Bilateral headaches lasting 30 minutes - 6 hours; pain is constant without photophobia, phonophobia, or aura
Treatment: Anangesics, NSAIDs, acetaminophen; Amitriptyline for chronic pain
Migraine Headaches
Unilateral, pulsating headaches lasting 4-72 hours; accompanied by nausea, photophobia, phonophobia, or aura
Treated with abortive therapies (NSAIDs, Triptans) and prophylactic (Propanolol, Topiramate, CCBs, Amitriptyline)
Primary Brain Tumors of Adults - 5
Glioblastoma Multiforme Meningioma Hemingioblastoma Schwannoma Oligodendroglioma Pituitary adenoma
Glioblastoma Multiforme
i.e. Grade IV astrocytoma; most common primary brain tumor of adults with poor prognosis (median survival = 1 year)
Usually occurs in the cerebral hemispheres; can cross the corpus callosum (“butterfly glioma”)
CT/MRI shows ring-enhancing lesion
Histology shows “pseudopalisading” pleomorphic tumor cells surrounding central hemorrhage/necrosis
Meningioma
Common, usually benign tumor arising from the arachnoid, usually in the cerebral convexities
Often asymptomatic +/- seizures, focal neuro deficits
Histology shows “spindle-like” cells +/- Psammoma bodies
Treatment: Resection +/- radiation
Schwannoma
Tumor of Schwann cell origin, usually seen at the cerebellar-pontine angle with involvement of CN VIII (bilateral acoustic schwannomas seen in NF-2)
Hemangioblastoma
Malignant proliferations of closely packed, thin-walled capillaries; most often cerebellar
May produce EPO causing secondary erythrocytosis
Associated with VHL when seen with retinal hemangiomas
Oligodendroglioma
Slow growing tumor of oligodendrocytes; usually found in the frontal lobes
Histology shows tumor cells with “fried egg appearance” (round nuclei surrounded by clear cytoplasm)
Lacunar Infarct
Infarction of the lenticulostriate arteries, penetrating branches off of the MCA which supply the internal capsule and basal ganglia
Often seen in the setting of long-standing HTN
Kluver-Bucy Syndrome
Caused by bilateral damage to the amygdala, often secondary to ischemic stroke
Presents with hypersexuality, hyperorality, and disinhibited behavior
Gerstmann’s Syndrome
Caused by lesion of the angular gyrus in the visual association cortex
Presents with inability to distinguish left from right, inability to recognize fingers, inability to understand arithmetic (acalculia), inability to write (agraphia)
Broca’s aphasia
Caused by lesion of Broca’s area in the inferior gyrus of the frontal lobe
Characterized by non-fluent speech with in-tact comprehension; patients can understand and form thoughts but cannot generate speech, leading to frustration
Wernicke’s aphasia
Caused by lesion of Wernicke’s area in the superior gyrus of the temporal lobe
Characterized by fluent speech with impaired comprehension (gibberish)
Conduction aphasia
Caused by lesion of the arcuate fasciculus, connecting Broca’s and Wernicke’s areas
Characterized by fluent speech and intact comprehension but impaired repetition
Global aphasia
Caused by lesion of arcuate fasciculus + Broca’s area + Wernicke’s area
Characterized by non-fluent speech and impaired comprehension
Tyramine reaction
Adverse drug interaction seen with use of non-selective MAOIs; decreased metabolism of NE, Epi, DA, 5-HT and tyramine (found in wine, cheese) may cause hypertensive crisis
Also seen with concomitant use of sympathomimetics (SSRIs, TCADs) - “serotonin syndrome”
