As with any other type of seizure, it is most important to make sure that the episode is, indeed, a seizure. Detailed history from the patient and family members is important.

Diagnosing a simple partial seizure can be difficult, especially when sensory, autonomic, or psychic symptoms are predominant. Suspicion of simple partial seizure is based on typical history and reproducible patterns with known simple partial seizure types. A neurological examination may or may not show subtle focality. Some patients may have postepileptic paresis (Todd paralysis). Examination during a seizure is helpful to assess consciousness. The patient should be able to follow simple commands and remember the events postictally to make a diagnosis of simple partial seizure. Simple commands like moving extremity on both sides, repeating a two syllable command will help assess responsiveness. Some patients with motor manifestations may not be able to perform a motor task but remember the instructions postictally; this should be interpreted as intact responsiveness.

Symptoms depend on the area involved.

• Temporal lobe focal aware seizures can cause autonomic and/or psychological symptoms. The most common symptom is an epigastric rising sensation. Sometimes sensory symptoms like auditory and olfactory hallucinations can be present.
• Frontal lobe simple partial seizures are usually short but can have a rapid generalization. They have prominent motor manifestations like twitching or stiffness in one muscle group on one side.
• Parietal lobe Focal aware seizures present with predominantly sensory symptoms. They may have a feeling of tingling or numbness that may or may not spread in a Jacksonian manner. Head, arm, and face are most commonly involved. They can also present with visual metamorphopsia, loss of awareness of a body part, vertigo, and sometimes language disturbances.
• Occipital lobe seizures usually have visual manifestations like scotoma, amaurosis, or flashing lights. They also can have visual hallucinations and perceptive illusions in which objects appear distorted.  [1] [2][3][4][5]

Clinical data alone is often not enough to precisely diagnose and localize focal seizures. Scalp and intracranial EEG may be needed to diagnose accurately. EEG done after the suspected seizure episode may be normal or nonspecific. MRI head is required to identify the underlying etiology

Seizure characteristics that favor an epileptic diagnosis include younger age at onset, stereotyped patterns of movements, shorter duration of seizures, nocturnal occurrence and presence of MRI, and EEG abnormalities.

In general, patients suffering from partial seizures of unknown etiology or of structural origin should be treated with antiepileptic drugs.

Focal seizures caused by non–neurological pathologies like infections and electrolyte imbalance are managed by treating the underlying etiology.  It is important to know if the seizure fits into a particular type of epilepsy or epilepsy syndrome in order to decide treatment and determine prognosis. 

Medications

Appropriate seizure medication is chosen based on the type of seizure, side effect profile of the medication, the age of the patient, use of other medications and co-morbid medical conditions. Carbamazepine and lamotrigine are the first-line antiepileptic drugs (AED) for simple partial seizures. Alternative first-line drugs include valproate, oxcarbazepine, and levetiracetam. One of these medications should be considered if the other two are not tolerated or can not be used. If the first AED is ineffective or not tolerated, then another AED of these five drugs should be considered. If the second AED is also not effective, then adjunctive therapy is added. Adjunctive therapy for focal seizures includes carbamazepine, lamotrigine, levetiracetam, oxcarbazepine, sodium valproate, gabapentin, topiramate, and clobazam. If adjunctive therapy is also not effective or not tolerated, then referral to a tertiary epilepsy center should be considered, where other AED may be tried.

Ketogenic diet

AEDs can control seizures in about two-thirds of epilepsy patients. The ketogenic diet can help control seizures in some children. It is a specialized high fat, low carb and controlled protein diet, that should be considered in children with intractable seizures when at least two AEDs have been ineffective.  

Vagus nerve stimulation

Vagus nerve stimulation (VNS) involves an electric stimulator inside the body that connects to the left vagus nerve in the neck. It helps to calm down the irregular electrical activity in the brain. It can reduce the frequency, severity, and length of seizures. VNS therapy should be considered in patients whose seizures are not controlled with AEDs and are not candidates for surgery. Antiepileptic effects of VNS therapy may take up to two years, and AED should always be used along with it. If VNS therapy is effective, it may be possible to reduce the medications slowly.

Surgery

Surgery should be considered for refractory seizures where a specific area of the brain is responsible for causing seizures. Surgery involves removing or separating the specific area of the brain causing seizures.

Some conditions that initially can present like simple partial seizures include the following:

Absence seizures, hemifacial spasm, benign childhood epilepsy, Migraine variants, transient ischemic attack, hypoglycemia, cervical disc problems, myoclonus, panic attacks, and psychosis.

Patients with partial seizures have a higher risk of seizure recurrence than those with generalized seizures. However, recurrence rates of simple and complex partial seizures appear to be the same. Risk of seizure-related complications like aspiration, and overall morbidity and mortality are lower in simple partial seizures than in those where consciousness is impaired. 

Simple partial seizures can result in falls and trauma. Uncontrolled or poorly controlled seizures can cause chronic neurological and cognitive impairment. Prognosis of simple partial seizure is believed to be similar to that of complex partial seizure and is dependent on the underlying etiology of seizures.

Some special focal epileptic syndromes include the following:

Benign Epilepsy with Centrotemporal Spikes

Benign Epilepsy with Centrotemporal Spikes (BECTS) is a benign form of focal motor epilepsy in children, featuring centrotemporal spikes. It accounts for 6% to 10% of all childhood epilepsies. The age of onset is 3 to 13 years with a peak at 7 to 8 years. It is more common in boys. Some reports suggest autosomal inheritance. Centrotemporal spikes are characteristic of BECTS but not pathognomic, as they can be seen in more complex epilepsy syndromes as well. Seizures typically occur during sleep, either shortly after falling asleep or just before awakening. Classically, the unilateral lower face is involved with facial twitching, paresthesia, and dysarthria. Hemi convulsions may occur, especially in young children. They can rarely become generalized. The seizures are brief, occurring in clusters, followed by prolonged seizure-free intervals. Typical EEG findings are high amplitude diphasic spike or sharp waves with prominent aftercoming slow waves in the contralateral centrotemporal area. BECTS have an excellent prognosis, and most children achieve remission by puberty regardless of antiepileptic drug therapy. Pharmacotherapy is usually not needed in the majority of cases. Anti-seizure drugs like valproate may be used in severe cases or with frequent symptoms.[16]

Early-Onset Benign Occipital Epilepsy

Also known as panayiotopoulos syndrome, early-onset benign occipital epilepsy accounts for 1% to 2% of children with focal epilepsy. The age of onset is 3 to 8 years with a peak at 5 years. It is more common in girls. Seizures are almost always nocturnal and present with autonomic symptoms, most commonly nausea and vomiting. The seizure frequently lasts longer than 30 minutes, and about one-third of patients may develop focal status epilepticus.  Early-onset benign occipital epilepsy may evolve into generalized seizures, and consciousness may be impaired. Ictal EEG shows rhythmic theta or delta activity with intermixed spikes that start posteriorly. Most children have occasional seizures and do not require pharmacological treatment.[17]

Late-Onset Benign Occipital Epilepsy

Late-onset benign occipital epilepsy is also known as Gastaut type epilepsy.  It presents in mid to late childhood with a peak age of eight years. It manifests as frequent, often more than 15, brief visual seizures mostly visual hallucinations or blindness. Typically, there is no impairment in consciousness unless there is a secondary generalization.[17]

Epilepsia Partialis Continua

Epilepsia partialis continua is also known as partial continuous epilepsy and represents a type of focal motor status epilepticus. It is characterized by continuous rhythmic or semi rhythmic clonic movements of one muscle group that remain localized and continue for hours, days, weeks, or months without spreading to other parts of the body. Any muscle group can be affected, but distal musculature is more commonly affected. They may develop at any age. Several acute or chronic cerebral lesions may cause these partial seizures. These seizures are often mistaken for slow tremors or movement disorders. They are particularly common in Rasmussen syndrome. This type of seizure activity responds poorly to AEDs, and all patients should be evaluated for an underlying lesion that may be amenable to surgical treatment.[18]

Supplementary Sensorimotor Seizures

These seizures originate from the supplementary sensorimotor area (SSMA) and are characterized by rapid onset, asymmetrical posturing involving one or more extremities. Typically, both sides of the body are affected. These seizures are usually brief, lasting 10 to 40 seconds, but may be frequent, occurring in clusters. SSMA seizures tend to occur during sleep. Speech arrest and vocalization can happen during these episodes. Consciousness is typically preserved. Only a few patients who experience SSMA seizures actually have SSMA epilepsy. These seizures can get misdiagnosed as nonepileptic or psychogenic seizures because the involvement of all extremities with preserved consciousness can be misleading.[19]

Patients with partial seizures are at high risk of seizure recurrence. An interprofessional team of nurses and the neurologist should assist in educating the patient and family in methods to avoid seizure-related complications such as aspiration and when to call an ambulance if a seizure is sustained. [Level V]