Todd's Paralysis Health Article

Definition

Todd's paralysis is a brief period of paralysis that occurs in the aftermath of a seizure.

Description

The period of time directly following a seizure is called the "postictal state." During this time period, the individual's brain is still recovering from the major changes brought on by the seizure. Drowsiness and confusion are very common symptoms of the postictal state. In some cases, the symptoms are even more pronounced and dramatic, and may even involve severe weakness or paralysis of a limb or one side of the body (hemiparesis), odd sensations such as numbness, or pronounced vision changes or blindness.

Demographics

Todd's paralysis usually strikes individuals who have epilepsy (recurrent seizures), although it may occur after any seizure.

Causes and symptoms

A seizure is an episode of abnormal electrical activity in a particular part of the brain. There are many kinds of seizures, and they may affect any specific part of the brain, or may spread to affect a wider distribution of the brain. The behavior of an individual suffering from a seizure may range from a simple, brief staring episode to complete loss of consciousness, with involuntary jerking of the muscles. The aftermath of a seizure is referred to as the postictal state. During the postictal period, although the seizure itself has ended, the brain is still recovering from the abnormal electrical discharges that precipitated the seizure activity. During this time period, the individual may be drowsy, less responsive than normal, or confused. Todd's paralysis is thought to occur due to depressed activity in the area of the brain that underwent the seizure.

The symptoms of Todd's paralysis depend on the area of the brain where the seizure took place. For example, if the seizure occurred in the motor cortex (that part of the brain responsible for purposeful movement of the muscles), Todd's paralysis may result in hemiparesis, an inability to move the muscles of one-half of the body. Because the occipital lobe (the lower back part of the brain) is responsible for vision, an occipital lobe seizure may result in visual change or outright blindness during the postictal phase. In fact, tracking the specific symptoms of Todd's paralysis may actually help the physician diagnose the specific area of the brain in which an individual's seizures are occurring.

The symptoms of Todd's paralysis are often gone within minutes or hours of their onset. In some, more rare cases, the symptoms may last as long as 48 hours. Ultimately, however, full function is restored.