Treatment for MELAS Syndrome Exacerbations
L-arginine therapy is the primary treatment for MELAS syndrome exacerbations, with intravenous administration recommended for acute stroke-like episodes and oral administration for maintenance therapy to prevent recurrences. 1, 2, 3
Acute Management of Stroke-like Episodes
For acute stroke-like episodes, administer L-arginine hydrochloride intravenously using weight-based dosing:
Intravenous L-arginine therapy can improve acute symptoms including:
- Headache
- Nausea/vomiting
- Impaired consciousness
- Visual disturbances 1
Monitor for potential adverse effects during IV administration:
Maintenance Therapy and Prevention
For prevention of stroke-like episodes, oral L-arginine should be administered at the same dosing as acute treatment:
Oral L-arginine maintenance therapy helps extend the interictal phase between stroke-like episodes 1
Dosage adjustments may be necessary for patients with renal impairment 3
Adjunctive Therapies
Coenzyme Q10 and its synthetic analog idebenone support mitochondrial function and can be used as adjunctive therapy 1, 2, 4
B vitamins, particularly riboflavin, help support the electron transport chain 2, 5
Vitamin C provides antioxidant support for mitochondrial function 2
Levocarnitine may be beneficial for supporting mitochondrial function 5, 4
In refractory cases, a ketogenic diet may be considered as it may improve mitochondrial respiratory chain complex function, potentially leading to better seizure control and less frequent stroke-like episodes 6
Monitoring During Treatment
Monitor serum lactate levels to assess treatment response 1, 4
Assess for improvement in neurological symptoms, including headache, seizures, and altered consciousness 1, 7
Regular cardiac evaluation is recommended due to potential cardiac conduction defects associated with MELAS 1, 5
Monitor for diabetes mellitus, which commonly occurs in MELAS patients 1, 5
Clinical Pearls and Pitfalls
MELAS stroke-like episodes do not conform to specific arterial territories and preferentially involve the posterior cerebral hemispheres, distinguishing them from typical ischemic strokes 1, 2
Misdiagnosis as herpes simplex encephalitis or conventional ischemic stroke is common and can delay appropriate treatment 8
The pathophysiology involves both energy deficiency and nitric oxide deficiency, which explains the therapeutic benefit of L-arginine 4, 7
Early initiation of L-arginine therapy is crucial for optimal outcomes in acute stroke-like episodes 7
The rare nature of MELAS makes generating high-quality evidence challenging, but current evidence strongly supports L-arginine as the primary treatment 1