A 15-year-old boy is brought to the office because of 3 months of sudden, brief jerking movements involving both arms. The episodes usually occur shortly after awakening in the morning and are aggravated by sleep deprivation. The movements are neither suppressible nor preceded by an urge to make a movement. The patient has never lost consciousness and has no known medical conditions. Family history includes a seizure disorder in his uncle. Vital signs are within normal limits. Physical examination shows normal development with no abnormalities. Which of the following is the best initial treatment for this patient?
Seizure types | Medication | |
Generalized onset (both hemispheres) | ||
Tonic-clonic |
| Broad spectrum*: levetiracetam, valproic acid |
Myoclonic |
| |
Atonic |
| |
Absence |
| Ethosuximide |
Focal onset (single hemisphere) | ||
Aware |
| Narrow spectrum: phenytoin,** carbamazepine, gabapentin |
Impaired awareness |
| |
*Can be used for both generalized & focal seizures. **Can be used for management of status epilepticus. LOC = loss of consciousness. | ||
This patient most likely has myoclonic seizures due to juvenile myoclonic epilepsy (JME), a form of generalized onset epilepsy (ie, affecting both cerebral hemispheres at onset) that may be familial. Typically, JME manifests in an otherwise healthy adolescent with myoclonic seizures (ie, brief, involuntary jerking movements) involving both upper extremities with preservation of consciousness. Symptoms usually occur within the first hour of awakening and can be provoked by sleep deprivation. Patients can also develop tonic-clonic and/or absence seizures.
Treatment of generalized onset epilepsies like JME should include a broad-spectrum anticonvulsant (eg, valproic acid, levetiracetam) which can treat both focal and generalized seizures. In contrast, narrow-spectrum anticonvulsants (eg, carbamazepine, phenytoin) are primarily used only in patients with focal onset seizures and can worsen seizure symptoms in patients with absence or myoclonic seizures (Choice B).
(Choice A) Baclofen is a GABA-B agonist that can treat chronic muscle spasticity (eg, cerebral palsy). Patients with chronic muscle spasticity typically have progressive changes in development and muscle tone that would be apparent on physical examination.
(Choice C) Clonidine is an alpha-2 adrenergic receptor agonist that may be effective in children with attention-deficit hyperactivity disorder who have failed treatment with stimulants (eg, methylphenidate).
(Choice D) Diazepam is a benzodiazepine that can be used acutely to treat prolonged seizures such as status epilepticus (≥5 minutes of continuous seizure activity or >1 seizure without recovery in between). However, diazepam would not be indicated for this patient's brief episodes of myoclonus.
(Choice E) Propranolol is a nonselective beta blocker that can treat benign essential tremor, which typically presents in middle-aged adults with bilateral, rhythmic hand tremor that worsens during fine motor activity.
(Choice G) Tetrabenazine is a dopamine depletion agent that can treat Tourette syndrome, a disorder characterized by motor and phonic tics that persist for >1 year. Motor tics can manifest as periodic, sudden, jerking movements, but they are usually temporarily suppressible and often preceded by an urge to make the stereotyped movement.
Educational objective:
Broad-spectrum anticonvulsants (eg, levetiracetam, valproic acid) treat both focal and generalized onset seizures, whereas narrow-spectrum anticonvulsants (eg, carbamazepine, phenytoin) are primarily used only for focal onset seizures. Because the seizures in juvenile myoclonic epilepsy are usually generalized onset (ie, affect both cerebral hemispheres at onset), treatment is with a broad-spectrum agent such as valproic acid.