Epilepsy is defined as repetitive, often stereotypic seizures, but even a single seizure coupled with a significant abnormality on neuroimaging or a diagnostic electroencephalogram (EEG) can signify epilepsy.

Epilepsy is characterized by sudden, transient alterations of brain function, usually with motor, sensory, autonomic, or psychic symptoms; it is often accompanied by alterations in consciousness.

Coincidental pronounced alterations in the electroencephalogram (EEG) may be detected during these episodes.

The epilepsies are a heterogeneous group of disorders. In the broadest sense, they can be categorized into disorders characterized by generalized or partial (focal, local) seizures. Some types of seizures are due to lesions in specific parts of the brain and thus have localizing value.

Focal (Jacksonian) Epilepsy

Seizures resulting from focal irritation of a portion of the motor cortex may be manifested within the corresponding peripheral area. These are termed focal motor seizures, and they suggest damage to a discrete, specific part of the brain. For example, if the motor cortex for the hand is involved, the seizure may be confined to the hand. Consciousness may be retained, and the seizure may spread over the rest of the adjacent motor cortex to involve adjacent peripheral parts. The spread of seizure activity, as it extends over the homunculus on the motor cortex, may take the form of an orderly “march” over the body (see Fig 10–14). Focal motor seizures can occur with or without a march. This type of seizure is most commonly associated with structural lesions such as brain tumor or glial scar. Electrical stimulation of the exposed cortex during neurosurgery has aided in mapping the cortex and in understanding localized, partial seizures. For example, electrical stimulation of various regions within the primary motor cortex results in movement of specific body parts (see Fig 21–8), in accordance with the organization of the motor homunculus as shown in Figure 10–14.

Image not available.

Results of electrical stimulation of the cerebral cortex.

Complex Partial Epilepsy

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There are several types of complex partial epilepsy. In temporal lobe epilepsy, the seizure may begin with psychic or complex sensory symptoms (eg, a feeling of excitement or fear, an abnormal feeling of familiarity—déjà vu; complex visual or auditory hallucinations) or autonomic symptoms (eg, unusual epigastric sensations). Olfactory or gustatory sensations are often reported. These may be followed by automatisms, simple or complex patterned movements, incoherent speech, turning of the head and eyes, smacking of the lips or chewing, twisting, and writhing movements of the extremities, clouding of consciousness, and amnesia. Complex acts and movements such as walking or fastening or unfastening buttons may occur for periods of several seconds or as long as 10 minutes. Temporal lobe foci (spikes, sharp waves, or combinations of these) are frequently associated with this type of epilepsy. These complex partial seizures may, in some patients, generalize so that the patient has tonic–clonic seizures. Pathology in the temporal lobe (eg, glial scarring or a tumor) is often present.

 

Status Epilepticus

Status epilepticus refers to 30 min or more of continuous seizure activity or two or more seizures without recovery of consciousness between seizures.

Initial Supportive Care

  • 1. Maintain airway with cervical spine precautions.
  • 2. Deliver oxygen by nasal cannula.
  • 3. Monitor ECG and blood pressure.
  • 4. Maintain normal temperature.

Pharmacologic Therapy

  • 1. Establish IV, administer thiamine 100 mg IV (Table 21–6).
  • 2. Administer 1 amp of D50 IV in an adult (2 mL/kg D25 in children) unless obviously hyperglycemic.
  • 3. Administer IV lorazepam or diazepam initially (midazolam 0.2 mg/kg); can be given IM in children if no IV.
  • 4. If seizures persist, give fosphenytoin or phenytoin.
  • 5. If seizures persist, give phenobarbital, paraldehyde.
  • 6. If still no response, obtain emergency neurosurgery and anesthesiology consultations.
Drugs for the Management of Status Epilepticus
Drug Pediatric Dose (mg/kg) Adult Dose Maximum Rate (mg/min)
Diazepam (Valium) 0.10–0.20 IV 5–10 mg IV (up to 30 mg) 3–5
Fosphenytoin NA 20 mg/kg IV 150
Paraldehyde a 0.15–0.3 mL/kg PR 30 mL PR NA
Phenytoin (Dilantin)b 15 IV Same as for child 50
Phenobarbitalc 10 IV or IM 120–140 mg IV 100

NA = not applicable.

aWhen given rectally, mix 2:1 with cottonseed or olive oil.

bWhen given IV, use a maximum dose of 50 mg/min and monitor ECG and vital signs closely. Can cause severe hypotension and bradycardia. Mix with NS to prevent precipitation.

cIndicated when the patient is allergic to phenytoin, patients may need intubation.

 

 

 

Epilepsy is usually defined as repetitive, often stereotypic seizures, but even a single seizure coupled with a significant abnormality on neuroimaging or a diagnostic electroencephalogram (EEG) can signify epilepsy.

 

Dysfunction of the cerebral cortex, alone or together with dysfunction of deeper structures, can lead to some forms of epilepsy.

 

 

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Complications of Injecting Drug Use

  • Local problems—Abscess (Figures 240-2 
    Image not available.

    A 32-year-old woman with type 1 diabetes developed large abscesses all over her body secondary to injection of cocaine and heroin. Her back shows the large scars remaining after the healing of these abscesses. (Courtesy of ­Richard P. Usatine, MD.)

    and 240-3; Abscess), cellulitis, septic thrombophlebitis, local induration, necrotizing fasciitis, gas gangrene, pyomyositis, mycotic aneurysm, compartmental syndromes, and foreign bodies (e.g., broken needle parts) in local areas.2
    • IDUs are at higher risk of getting methicillin-resistant Staphylococcus aureus(MRSA) skin infections that the patient may think are spider bites (Figure 240-4).
    • Some IDUs give up trying to inject into their veins and put the cocaine directly into the skin. This causes local skin necrosis that produces round atrophic scars (Figure 240-5).
  • IDUs are at risk for contracting systemic infections, including HIV and hepatitis B or hepatitis C.
    • Injecting drug users are at risk of endocarditis, osteomyelitis (Figures 240-6and 240-7), and an abscess of the epidural region. These infections can lead to long hospitalizations for intravenous antibiotics. The endocarditis that occurs in IDUs involves the right-sided heart valves (see Chapter 50, Bacterial Endocarditis).2 They are also at risk of septic emboli to the lungs, group A β-hemolytic streptococcal septicemia, septic arthritis, and candidal and other fungal infections.

 

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Content 11

 

This 44-year-old woman had a generalized tonic–clonic seizure associated with fever at the age of 3 but was otherwise well until the age of 12, when complex partial seizure activity began. Her seizures were characterized by an aura consisting of a rising sensation in her gut, followed by loss of consciousness, tonic activity of the left hand, and turning of the head to the left. Sometimes she would fall if standing. Her seizures averaged 5 to 10 per month despite treatment with anticonvulsant drugs. On examination, no neurologic abnormalities were observed. Because of the failure of traditional medical therapy to control her seizures, the patient was hospitalized. Electroencephalogram monitoring revealed slowing and abnormal spike activity in the right anterior temporal lobe. During her seizures there was abnormal discharge of the right temporal lobe. An intracarotid amobarbital test, in which an anesthetic was injected into her carotid arteries, demonstrated left-hemisphere dominance for speech and a marked disparity of memory function between the left and right hemispheres; the left hemisphere showed perfect memory and the right showed significantly impaired memory. Magnetic resonance imaging scanning showed severe atrophy of the hippocampus on the right (Fig 21–9).

Image not available.

Magnetic resonance image of frontal section through the head, showing hippocampal atrophy (arrow) in the patient described in Clinical Illustration 21–1.

The concordance of the EEG findings, together with MRI demonstration of right hippocampal atrophy, indicated right medial temporal lobe epilepsy. Because the patient's seizures had not been controlled by anticonvulsant medications, she underwent neurosurgical resection of the right medial temporal lobe (Fig 21–10). Subsequent to surgery, the patient has had no seizures with the exception of one that occurred when her anticonvulsant drug levels were very low.

Image not available.

Postoperative magnetic resonance image of frontal section through the head, showing anteromedial temporal lobectomy (arrow).

This case illustrates a classical history and findings for the most common form of epilepsy treated by surgery, medial temporal lobe epilepsy. The response to neurosurgical resection of these areas can be dramatic, with nearly 90% of patients being relieved of seizures. The correlation of anatomic localization by electrical, structural, and cognitive studies preoperatively and the subsequent response to resection of a circumscribed cerebral area provide a dramatic demonstration of anatomic–clinical correlation.

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