Metabolic and toxic encephalopathies and neuropathies

Metabolic and toxic encephalopathies and neuropathies are secondary, acquired disorders that arise as a result of changes in the internal environment of the organism, for example as a result of some internal diseases ("metabolic encephalopathies").

Anoxic ischemic encephalopathy
Etiology: hypotension, cardiopulmonary insufficiency

Causes: myocardial infarction, cardiac arrest, hemorrhagic shock, asphyxiation, CO intoxication


 * hypoxia mostly affects the cortex and subcortical structures

Clinical picture:
 * hypoxia → restlessness, anxiety, disorders of attention and motor coordination
 * anoxia → loss of consciousness, generalized convulsionse (tonic)
 * prolonged anoxia → coma (mydriasis, extinguished photoreaction) to brain death

Treatment: nootropics

Posthypoxic (postanoxic) syndrome: persistent coma or other disorders of consciousness, apalic syndrome, dementia, parkinsonian syndrome, cerebellar syndrome, choreoathetosis, Korsak amnestic syndrome, intentional or action myoclonus

Hypercapnic encephalopathy
Etiology: increased partial pressure of CO2 → chronic emphysema, respiratory insufficiency, chronic respiratory acidosis

Clinical picture: headaches, somnolence, psychomotor retardation, asterixis, possibly. confusion to coma

Hypoglycemic encephalopathy
Etiology: excessive dose or increased secretion of insulinu

Clinical picture: nervousness, headaches, palpitations, anxiety, sweating, tremors, motor restlessness, muscle spasms, myoclonus, hyperreflexia, ev. confusion to coma, epileptiform convulsions, focal neurological symptoms (convulsions, paresis)

Treatment: glucose i.v.

Hyperglycemic coma
Etiology: ketoacidosis, hyperosmolality, hypoxemia

Hepatic encephalopathy
Etiology: chronic liver insufficiency with portocaval shunt

Clinical picture: confusion, convulsions, asterixis, metabolic tremor, spastic pyramidal phenomena, ataxia standing and walking, choreoathetosis

Treatment: lactulose

Uremic encephalopathy
Clinical picture: fatigue, apathy, increased irritability, confusion, muscle twitches to myoclonus, metabolic tremor, asterixis, convulsions, epilethiform seizures

Endocrine encephalopathy
Causes:
 * administration of ACTH or corticosteroids

→ psychotic clinical picture


 * hypothyroidism

→ confusion, mania or depression, muscle weakness

Diabetic polyneuropathy
Etiology: chronic hyperglycemia

Alcoholic polyneuropathy
Etiology: deficiency, nutritional and vitamin deficiency (especially thiaminu), direct toxic effect of alcohol on peripheral nerves

Clinical picture: symmetrical mixed sensory and motor involvement acral on the lower limbs, dysautonomia, hyperhidrosis, axonal type neuropathy

Treatment: abstinence, adequate nutrition, vitamins B1 and B12

Toxic polyneuropathies
Etiology: organophosphates, carbon disulfide, lead, mercury, hexacarbons, isoniazid (therefore administer pyridoxine as a preventive measure), cytostatics (vincristine - therefore we administer with glutamic acid), amiodarone, statins

Related Articles

 * Toxoinfectious encephalopathy
 * Encephalopathy
 * Hyperglycemic Coma
 * Heavy metal poisoning
 * Alcohol intoxication
 * Anoxia

Literature


Done by: Eisa Jbara