KEY FACTS Terminology Many drugs (prescription, illicit, or street) have adverse CNS effects Illicit drug use often causes cerebrovascular disease Amphetamines, cocaine > opioids, cannabis Polydrug abuse (including EtOH) is common Nitrous oxide (NO₂) abuse → vitamin B12 inactivation →…
KEY FACTS Terminology Anoxic-ischemic encephalopathy, usually with bilateral lesions, caused by inhalation of carbon monoxide (CO) gas Imaging Best diagnostic clue: Globi pallidi (GP) T2/FLAIR hyperintensity T1 MR: Both hypointensity in GP (likely necrosis) and hyperintensity in GP (likely hemorrhage)…
KEY FACTS Terminology Idiopathic intracranial hypertension (IIH) Pseudotumor cerebri “Benign intracranial hypertension” ↑ intracranial pressure (ICP) without identifiable cause Imaging Empty or partially empty sella Posterior globe flattening Intraocular protrusion of optic nerve head Optic nerve sheath enlargement: Widened ring…
KEY FACTS Terminology Subcortical arteriosclerotic encephalopathy Imaging General features Lacunae (lenticular nuclei, pons, thalamus, internal capsule, caudate) Cerebral hemorrhage (basal ganglia/external capsule, thalamus) Confluent white matter (WM) disease (centrum semiovale, corona radiata) CT Diffuse WM hypodensity on CT Lacunar infarcts…
KEY FACTS Terminology Cerebrovascular autoregulatory disorder Many etiologies with HTN as common component Preeclampsia, eclampsia Drug toxicity (e.g., chemotherapy) Uremic encephalopathies Imaging General Patchy parietooccipital cortical/subcortical edema in patient with severe acute/subacute HTN CT Bilateral nonconfluent hypodense foci ± symmetric…
KEY FACTS Terminology Functional, potentially reversible clinical syndrome Acute hepatic encephalopathy (AHE) Chronic hepatic encephalopathy (CHE) Characterized by psychiatric, cognitive, and motor components Imaging AHE (hyperammonemia) High T2 signal in most of cerebral cortex (preferential insular cortex and cingulate gyri)…
KEY FACTS Terminology Acute/subacute/chronic toxic effects of EtOH on CNS Wernicke encephalopathy (WE) Marchifava-Bignami disease (MBD) Imaging EtOH: Disproportionate superior vermian atrophy, enlargement of lateral ventricles, sulci with chronic EtOH WE: Mammillary body, medial thalamus, hypothalamus, periaqueductal gray abnormal signal/enhancement/diffusion…
KEY FACTS Terminology Fahr disease (FD) a.k.a. cerebrovascular ferrocalcinosis, bilateral striopallidodentate calcification Rare degenerative neurological disorder Extensive bilateral basal ganglia (BG) calcifications (Ca++) ± progressive dystonia, parkinsonism, neuropsychiatric manifestations Imaging Bilateral symmetric Ca++ in BG, thalami, dentate nuclei, and cerebral…
KEY FACTS Terminology CNS manifestations related to parathyroid hormone (PTH) metabolic abnormalities Hyperparathyroid (HPTH); hypoparathyroid (HP) Imaging Bilateral symmetric calcifications in globi pallidi, putamen, caudate nuclei Diffuse patchy “salt & pepper” lesions in skull in primary HPTH Plaque-like dural calcification,…
KEY FACTS Terminology Hashimoto encephalopathy (HE) HE synonym: Steroid-responsive encephalopathy associated with autoimmune thyroiditis Imaging Pituitary hyperplasia (PH): Symmetrical pituitary enlargement that is reversible with thyroid hormone replacement therapy Basal ganglia variably hyperintense (Ca++) HE: Bilateral patchy or confluent subcortical…