Generalized Tonic-Clonic Epilepsy Seizures (Grand Mal Seizures) – Clinical Presentation

Generalized Tonic-Clonic Epilepsy Seizures (Grand Mal Seizures) – Clinical Presentation

Epilepsy is a chronic cerebral disorder characterized by recurrent and spontaneous seizures that are typically unprovoked and unpredicteble.

An epilepsy seizure represents a transient episode of supratentorial origin, characterized by an abrupt and temporary alteration of cerebral function, due to an abnormal paroxysmal discharge of cerebral neurons caused by cortical hyperexcitability. According to The International Classification of Seizures, epilepsy seizures are divided into partial seizures ( focal or localization-related seizures) and generalized seizures.

Partial seizures are subdivided into simple partial seizures in which there is no loss of consciousness and into complex partial seizures which are always associated with loss of consciousness. Partial seizures are the result of an abnormal paroxysmal discharge of cerebral neurons within a particular brain region and they manifest focal symptoms an may progress to generalized seizures.

Epilepsy Seizures

Generalized seizures are the result of an paroxysmal discharge that probably begins in thalamus and then spreads to other brain structures, but on electroencephalographic (EEG) recordings, they appear to start simultaneously in both cerebral hemispheres. Generalized seizures are always associated with loss of consciousness and generalized symptoms.

Generalized Tonic-Clonic Epilepsy Seizures (Grand Mal Seizures)

Grand mal seizures or primary generalized seizures represent the most frequent form of epilepsy seizures and typically include four phases, out of which the first two phases may be absent, but the third phase is always present. This four phases are represented by prodromal phase, aura, tonico-clonic phase and postictal phase.

Prodromal Phase or Prodrome

This phase is present in 20%-30% of patients with epilepsy and may last for several hours up to maximum two days. Patients may experience mood changes, headache, depression, irritability, euphoria, paresthesia, hypoacusia, palpitation, pollakiuria (abnormally frequent urination), diffuse myoclonia, sleep disturbances and difficulty concentrating. This symptoms are sometimes observed by family members and not by the patient.

Aura

This phase is present in 50% of patients with epilepsy and lasting seconds (5-15 seconds). Aura predicts the loss of consciousness an patients may experience symptoms such as palpitations, paresthesias, photopsias (the presence of perceived flashes of light), tinnitus, olfactory or taste hallucinations. Sensory-autonomic symptoms such as abdominal pain, facial pallor, headache or stereotypical ictal cry are more common and are followed by the loss of consciousness.

Epilepsy Seizures

Aura symptoms warn about the imminent crisis and patient may lay down before losing consciousness, thus avoiding a trauma caused by an eventual fall. Aura occurs every time  in the same manner in the same individual.

Tonico-Clonic Phase

Tonic-clonic phase of convulsive stage has a brutal onset with loss of consciousness and fall, with the possibility of injury occurrence. It evolves in two subphases: the tonic phase that lasts 15-20 seconds and the clonic phase that lasts 30-40 seconds.

Tonic phase begin with generalized muscle contracture, during which the patient utters a cry (due to forced expiration with closed glottal orifice).  Tonic phase is associated with loss of consciousness and is followed by an unprotected fall. The tonic phase begins with flexion of the trunk and elevation and abduction of the elbows. Subsequent extension of the back and neck is followed by extension of arms and legs. This events are accompanied by apnea which is leading to cyanosis, due to intense oxygen consumption induced by muscle contraction.

Autonomic signs are characteristic for this phase and are represented by profuse sweating, tracheobronchial hypersecretion, increase in pulse rate and in blood pressure. Although urinary bladder pressure is increasing during tonic phase, voiding does not occur due to sphincter muscle contraction.

Grand Mal Seizure

Clonic phase follows the tonic phase, in which the tonic muscles relax intermittently for a variable period of time and is characterized by saccadic and sychronous convulsive movements. This convulsive movements are initially reduced in amplitude and in speed and become increasingly ampler while the general hypertonia subsides. This atonic phases alternate with repeated violent flexor spasms and each spasm is accompanied by pupillary contraction and dilation. Patient may bite its tongue or cheeks.

Due to atonia which is characteristic for the end of this phase, voiding may occur as sphincter muscles relax. In clonic phase cyanosis subsides as respiration is regained.

Postictal Phase

This phase is considered a postcritic coma state and lasts from 1-5 minutes up to 20-25 minutes. This phase is always present in epilepsy grand mal seizures. The postictal phase is accompained  by a variable period of unconsciousness during which the patient becomes quiet and breathing resumes. The patient gradually awakens and after a period of stupor or sleep may present obnubilation, spatial and temporal disorientation, motor automatism, aggressivity and motor restlessness. Head ache and muscle weakness are common during this phase.

Generalized Tonic-Clonic Epilepsy Seizures Clinical Forms

In medical practice, particular variants of generalized tonic-clonic epilepsy seizures are encountered, such as:

1. In newborns, sychronous muscle contraction are substituted by chaotic muscle contraction of different body segments, due to cerebral immaturity;
2. In children, tonic phase is prolonged and may lead to sever functional consequences due to cerebral anoxia and respiratory failure during the crisis or grand mal crisis may be represented by an akinetic crisis associated with loss of consciousness and of muscle tone ;
3. In older patients, with vascular epilepsy, grand mal crisis present only the clonic phase which is not so dangerous as the tonic phase is absent.