Metabolic (2) Flashcards
Can be the result of insufficient food intake, through systemic diseases (primary hyperinsulinism, severe liver disease, or adrenal insufficiency) or through exposure to drugs that cause hypoglycemia (insulin)
hypoglycemia
S/S of hypoglycemia
patients typically present with headache, confusion, irritability, incoordination, and lethargy that lead to stupor and coma
What areas on MRI do we notice changes in when pt has hypoglycemia
MRI shows signal changes in the temporal, occipital, and insular cortices, hippocampus, and basal ganglia, often with thalamic sparing
How do we tx hypoglycemia
Prolonged or recurrent bouts of hypoglycemia can lead to permanent brain damage in survivors
Treatment of hypoglycemia depends on the cause
Restoration of glucose for exogenous causes
Removal of endogenous causes (liver, pancreatic, or adrenal tumors)
Can cause a broad variety of clinical issues involving numerous organ systems.
Brain and muscle involvement are common, but involvement of the GI tract, heart, and/or peripheral nerves are also often present
Mitochondrial disorders
Inheritance and diagnosis of mitochondrial disorders
Multigenerational disease shows maternal inheritance
Mitochondrial proteins are encoded within the mitochondrial and nuclear genome, complicating diagnosis
Diagnosis is based on a battery of clinical, imaging, pathological, and molecular assays
Mutations associated with mitochondrial disorders
Specific mutations in the mitochodrial genome are associated with specific diseases, but most patients with mitochondrial disease do not fit these specific syndromes
There are also ~1000 nuclear genes that can contribute to mitochondrial phenotypes, and mitochondrial diseases are thought to be vastly underdiagnosed
Options for Dx mitochondrial disease
Clinical history/Imaging
Muscle biopsy pathology (light microscopic level)
Muscle biopsy pathology (EM level)
Electron transport chain activity testing
Mitochondrial DNA (mtDNA) content quantification
Genetic testing (for nuclear and/or mitochondrial genomes)
10 year old boy with a history of epilepsy, progressive weakness, ataxia, hearing and vision deficit, and autonomic dysfunction
MRI of the brain showed a cyst and general atrophy
Muscle biopsy was performed to evaluate dor mitochondrial diseas
Mitochondiral myopathy
from large single mtDNA mutation, pigment retinopathy + opthomapletia before 20 yo
Kears-Sayre Syndrome:
see ragged red fibers and epilepsy
Usually caused by heteroplasmic point mutations in mt-tRNALys
Myoclonic epilepsy with ragged red fibers (MERRF)
Usually caused by large single mtDNA mutation
Causes pigmentary retinopathy and opthalmoplegia before 20 years of age
Kears-Sayre Syndrome (KSS)
Leighs is a mitochondrial syndrome caused by a _______ and is _______
nuclear mutation
auto. REcessive
arrest of development, hypotonia, seizures, extraocular palsies and LACTIC acidemia
Death between 1 and 2 years
Leighs
In Leighs there is enzyme deficiency in pathway converting ____ to _____
Decreased activity of ________
pyruvate to ATP
cytochrome C oxidase
Gross specimen shows perventricular grey matter destroyed (around cerebral aqueduct) adn see cavitated lesions that look like stroke but lack a pattern we see in stroke
Leighs
Seen predominantely in malnourished chronic alcoholicsà starvation/hemodialysis/gastric stappling/ GI surgery/ Hyperalimentation w/out thiamine supplementation
Thiamine deficiency: see Wenicke encephalopathy and Korsakoff
Lesion in mammillary bodies, dosomedial thal and 3/4th ventricles.
Opthalmoplegia, nystagmux, ataxia, confusion–> coma
Wernikes
How does wernikes present acutely and chronically
Acute look gray-brown + peticheal hemorrhage,
Chronic see atrophy + mammillary discolored
loss of anterograde episodic memory, confabulation, preserve intellegenc + learned shit
From repeat wernickes and see damage to medial dorsal thalamus + mammillary bodies
Korsakoff Psychosis
Usually due to pernicious anemia (40% of untreated patients)
Clinical: Ataxia, Romberg, spasticity, decreased reflexes, mental status changes
Vit B 12 deficiency
Spinal cord: anterior and lateral corticospinal tracts and posterior columns are vacuolated and demyelinated
seen in vit B12 deficiency
Carbone Monoxide: Irreversibly binds to hemoglobin, displacing oxygen
and Binds to areas rich in iron :
(globus pallidus, substantia nigra) & causes necrosis
What does acute CO poisoning look like
Acute CO poisoning
What structures are damaged in chornic CO poisoning?
see bilataeral pallidal cavitation
Clinically – truncal ataxia, nystagmus & limb incoordination
Cerebellar degeneration: Atrophy, especially of anterior superior vermis
Dropout of Purkinje cells, internal granular cells, and astrocytosis
Chornic ethanol toxicity
Alcoholism see:
Clinically – truncal ataxia, nystagmus & limb incoordination
and in brain______ degeneration
Atrophy, especially of _______
Dropout of _______
Cerebellar
anterior superior vermis
Purkinje cells, internal granular cells, and astrocytosis
Microcephaly, Cerebellar dysgenesi, Heterotopic neurons seen in
Describe face of FAS
Growth retardation
Facial deformities – short palpebral fissure, epicanthal
folds, thin upper lip, growth retardation of jaw
Cardiac defects – atrial septal defect
Delayed development and mental deficiency
Describe radation toxicity
Clinical symptoms of a mass lesion
Pathology: Large areas of coagulative necrosis, primarily in white matter and Vessels with marked thickened walls
Induction of neoplasms (meningiomas, sarcomas, gliomas) years after treatment
Intrathecal or intraventricular admin in combination with radiation may produce
Disseminated necrotizing leukoencephalopathy
Particularly around ventricles and deep white matter
Coagulative necrosis with axonal loss and mineralization
MEthotrexate poisoing
P.O. admin – sensory neuropathy
Intrathecal admin – axonal swelling
Vincristine poisoing
Ataxia, nystagmus, slurred speech and sensory neuropathy
Atrophy of cerebellar vermis and loss of Purkinje cells and granule cells
Phenytoin
Seizures, strokes, hemorrhages
Infarcts and hemorrhages due to vasospasm, emboli, hypercoaguability, hypotension, drug contaminants
Occasionally vasculitis (? Allergic)
Cocaine
Infarcts and hemorrhages
Attributed to vasculitis and hypertension
Amphetamine
