Partial Epilepsy Seizures – Clinical Presentation
Epilepsy is a chronic cerebral disorder manifested by recurrent, spontaneous seizures. An epileptic attack or a seizure represents an acute stereotype of dysfunctional motor, sensitive or sensorial behavior which is associated with loss of consciousness. Epilepsy is caused by a sudden 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 (tonic-clonic seizures and absence seizures).
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. 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.
A single epilepsy seizure does not constitute a diagnosis of epilepsy, but recognizing a seizure is the first step in the workup for a possible diagnosis of epilepsy. Complex partial seizures represent the most commonly manifestation of temporal lobe epilepsy.
Partial Epilepsy Seizures
Partial or focal epilepsy seizures are divided into motor, sensory, sensorial and autonomic seizures, according to the neuronal area involved in epilepsy attack and clinical manifestation. Partial seizures may evolve to a complex partial seizure (with loss of consciousness) or to generalized epilepsy seizures.
Partial Motor Seizures
- Motor jaksonian seizures represent the consequence of a lesion located into the ascending contralateral frontal gyrus. This seizures consist of repetitive movements or repetitive muscle contractions which may affect a body segment or may extend to the entire hemibody and include signs with or without march, versive movements and posturing.
- Adversive seizures are the result of a lesion located into the 8th Brodman area of the frontal lobe and consist of oculocephalic deviation opposite to the focal lesion.
- Oprecular seizures consist of hypersalvation and masitcation movements due to a lesion in the rolandic operculum.
- Aphasic seizures characterized by receptive or expressive transient aphasia due to lesions in area 22 of the temporal lobe or in area 44 of the frontal lobe.
- Phonatory seizures characterized by speech blockade due to a fronto-temporal lesions.
Partial Sensory Seizures
Also known as sensory jaksonian crisis represent the consequence of a lesion located into contralateral ascending parietal gyrus. This attack consist of paresthesia which may affect only a body segment or can spread to the entire hemibody, according to the cortical somatotopy.
Partial Sensorial Seizures
- Visual crisis caused by lesions manly located in the occipital lobe, but with possibility of extension to parietal or temporal lobes. Visual crisis may be represented by an illusional crisis with a distorted perception of space and surrounding objects, or may be represented by hallucinatory crisis. This hallucinatory crisis are simple, with geometrical scintillations in controlateral visual field, and complex with figurative perception or with lack of recognition of surrounding objects and family members or friends.
- Auditory crisis generally related to the temporal lobe lesions, are represented by auditory illusions with perception of distorted sound or by auditory hallucinations with perception of elementary or complex sounds (voices, music) or with lack of recognition of familiar sounds.
Partial Autonomic Seizures (Autonomic Crisis)
Are the result of lesions located in the frontal lobe, hypothalamus, basal ganglia, temporal lobe and are represented by paroxysmal hyperhydrosis (abnormally increased perspiration), respiratory crisis (paroxysmal hyperpneea), paroxysmal hyperthermia, hypertension crisis or vagal crisis (bradycardia, hypotension, pallor and dyspneea).
Temporal Lobe Partial Seizures
Temporal lobe epilepsy is the result of chronic lesions localized in the medial portion and the hippocampal region of temporal lobe. A link between febrile condition in childhood and temporal lobe epilepsy has been suggested, but the exact role of febrile conditions remains unknown. Some studies suggested that human herpesvirus-6 represents the link between febrile conditions in childhood and later development of temporal epilepsy.
Temporal lobe partial seizures are divided into pyschosensorial crisis and pyschomotor crisis.
Psychosensorial crisis consist of olphactive and taste hallucinations along with affective symptoms such as sensation of intense happiness, fear and anxiety and cognitive symptoms such as sensations of familiarity ( déjà vu, déjà vecu) or sensations of estrangement (jamais vu, jamais vecu).
Psychomotor crisis are accompanied by impairment of consciousness and represented by:
- Minor automatism crisis are characterized by impaired consciousness associated with motor automatisms (dressing movements, automatic movements of hands and mouth), verbal automatisms (repetition of one word, of a sentence or a phrase) and gelastic automatisms (laughing accesses).
- Major automatism crisis are characterized by an important loss of consciousness and more complex motor behavior. In this type of crisis patients may walk into different places and sometimes may commit violent acts of which they don’t remember after the crisis.