Todd’s paralysis (postictal paralysis) is a transient central paresis or plegia in one or two limbs that appear after an epileptic paroxysm. It is a symptom of central nervous system exhaustion and may indicate the presence of a brain tumor and dysmetabolic disorders. It is possible to diagnose postictal paralysis only if an acute violation of cerebral circulation is excluded using MRI or CT of the brain. Additionally, electroencephalography, examination of cerebral vessels, assessment of the state of somatic organs, biochemical blood analysis are carried out. In the absence of organic pathology, specific therapy is not required, epilepsy is treated.
General information
For the first time, a case of motor disorders arising after epileptic paroxysm was described by the English neurologist Benkley Todd in 1855. Subsequently, disorders of movement in the extremities, appearing after the epiprime and having a transient character, were isolated into a separate clinical syndrome. Currently, several synonymous names are used in neurology in relation to it: “Todd’s paralysis”, “postictal paralysis”, “postepileptic paralysis”. Todd’s paralysis is most common in childhood, which is associated with immaturity of neurotransmitter systems and incomplete processes of myelination of nerve fibers in children. As a clinical syndrome, Todd’s paralysis always causes oncological alertness among doctors, since it often occurs with secondary epilepsy caused by a brain tumor. In addition, epileptic paroxysm in combination with motor disorders may be a manifestation of acute cerebrovascular accident, and therefore all patients with a first-time episode of postictal paralysis are subject to urgent hospitalization.
Causes
The etiopathogenesis of postepileptic paralysis is under study. Researchers assume that postictal motor disorders are associated with excessively developing inhibition processes occurring in the central nervous system. Most authors tend to consider this a result of neurotransmitter insufficiency and depletion of cerebral functions. Indeed, Todd’s paralysis is observed mainly in organic pathology of the brain (encephalitis, CNS tumors, disorders of cerebral hemodynamics) or in patients with severe concomitant disease (heart failure, liver failure, CRF, septic conditions, diabetes mellitus, tuberculosis, etc.), causing toxic, dysmetabolic or ischemic damage to the central nervous system. Clinical observations show that Todd’s paralysis can be triggered by an epileptic status lasting more than 30 minutes. Some patients are diagnosed with lipid metabolism disorders with an increase in triglyceride levels and a decrease in cholesterol concentration.
Symptoms
The main symptom is the blocking of arbitrary limb movements following the epiprime. Hemiparesis is most often observed — muscle weakness of the arm and leg of the same name, less often monoparesis — weakness in only one of the limbs. Paresis is of a central nature, accompanied by an increase in muscle tone and a decrease in the sensitivity of the affected limb. The severity of muscle weakness varies widely from mild paresis to complete plegia. The duration of motor disorders usually does not exceed 24 hours, but can be up to 2 days. Then there is a gradual recovery of muscle strength and, accordingly, voluntary movements. In some cases, after repeated episodes, postictal paralysis does not completely regress, the patient has some residual motor deficit.
Transient paralysis, as a rule, is noted after paroxysm of focal Jackson epilepsy, secondary generalized epiprimes, epistatus lasting more than half an hour. In some patients, Todd’s paralysis occurs with speech (motor aphasia) and visual (hemianopsia) disorders. In such cases, especially with the primary occurrence of postepileptic neurological deficit, differentiation with stroke is required.
Diagnostics
In favor of postictal paralysis, an epileptic history and indications of previously observed postictal paresis may indicate. When an episode of postepileptic paralysis occurs for the first time, it is extremely difficult for a neurologist to distinguish it from ACVA. This is possible only with urgent MRI or CT of the brain. In addition to identifying/excluding foci of ischemic or hemorrhagic stroke, these studies can determine the presence of brain tumor formation, hydrocephalus, signs of encephalitis. In the absence of data for organic cerebral pathology, dynamic monitoring of the patient is carried out. Complete regression of motor deficits within no more than 48 hours makes it possible to diagnose Todd’s paralysis.
In order to assess cerebral hemodynamics, angiography or MRI of cerebral vessels is prescribed. The study of the bioelectric activity of the brain is carried out using electroencephalography, supplemented with functional tests, if necessary. An assessment of the state of somatic organs is of no small importance. First of all, electrocardiography and ultrasound of the heart, a biochemical blood test, a study of lipid metabolism are carried out; according to indications, a consultation of a cardiologist and other specialists is carried out.
Treatment
The basis of therapy is antiepileptic pharmaceuticals (anticonvulsants), which allow to stop epileptic paroxysm and reduce the frequency of epiprimes. Individual selection of anticonvulsants is carried out by an epileptologist. The drugs of choice are valproic acid, lorazepam, phenytoin, diazepam. In the presence of pathology of internal organs and dysmetabolic disorders, their therapy and correction are carried out in parallel with the treatment of epilepsy.
If the pathology of the central nervous system is excluded, additional treatment of paralysis is not required. If hydrocephalus is detected, course therapy with diuretics (acetazolamide, furosemide) is prescribed together with potassium preparations. If CT and MRI data of the brain indicate the presence of a cerebral tumor, the patient is referred to a consultation with a neurosurgeon to resolve the issue of further therapeutic tactics.