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…
KEY FACTS Terminology Adult hypoglycemic encephalopathy Imbalance between glucose supply, utilization → brain injury Hypoglycemia: Sudden decrease in serum glucose level < 50 mg/dL Imaging Stroke/coma in adult diabetic on insulin replacement therapy (IRT) Parietal/temporal/occipital lobes, basal ganglia, ± hippocampi…
Approach to Toxic and Metabolic Disorders Acquired toxic and metabolic disorders of the brain result from a wide variety of agents, including toxic exposures, substance abuse, radiation, and chemotherapy, as well as metabolic alterations, including hypertension, hepatic failure, hypoglycemia, and…
KEY FACTS Terminology Wilson disease is also known as hepatolenticular degeneration Autosomal recessive disorder of copper metabolism Abnormal accumulation of copper in various tissues Particularly in liver, basal ganglia (BG), midbrain Imaging Usually normal MR in presymptomatic patients T1WI: Normal…
KEY FACTS Terminology Autosomal dominant neurodegenerative disease Loss of GABAergic neurons of basal ganglia (BG) Imaging Diffuse cerebral atrophy Caudate nucleus (CN) atrophy → frontal horns enlarged ↑ “Bicaudate” ratio (BCR) or Evans ratio Intercaudate distance divided by distance between…
KEY FACTS Terminology Pantothenate kinase-associated neurodegeneration (PKAN) Most common form of neurodegeneration with brain iron accumulation (NBIA) Mutated pantothenate kinase 2 gene ( PANK2 ) Formerly known as Hallovorden-Spatz disease Imaging Best diagnostic clue Highly suggestive of PKAN is eye-of-the-tiger…