In approximately half of cases the attacks, or episodes, occur in a time-related manner. Each attack is stereotypical; that is, in any given individual, the timing, frequency and severity of attacks is similar. Some affected people experience episodes that progressively get worse when left untreated, occurring more frequently with reduced symptom free phase.Episodes may happen every few days, every few weeks or every few months, for some happening at common uniform times, typically mornings. For other affected people, there is not a pattern in time that can be recognized. Some with the condition have a warning of an episodic attack; they may experience a prodrome, some documented prodromal symptoms include: unusually intense nausea and pallor, excess salivation, sweating, flushing, rapid/irregular heartbeat, diarrhea, anxiety/panic, food aversion, restlessness/insomnia, irritability, depersonalization, fatigue/listlessness, intense feelings of being hot or chilled, intense thirst, shivering/shaking, retching, tachypnea, abdominal pain/cramping, limb paresthesias, hyperesthesia, photophobia, phonophobia, headache, and dyspnea, heightened sensitivity, especially to light, though sensitivity to smell, sound, pressure, and temperature, as well as oncoming muscle pain and fatigue, are also reported by some patients. Many experiences a full panic attack when nausea begins and continue to panic once the vomiting has begun. Medications like Lorazepam, Alprazolam, and other benzodiazepines are prescribed by their doctors and instructed to take immediately at the onset of any of their CVS symptoms and/or triggers. Some prodromal symptoms are present inter-episodically as well as during acute phases of illness. The majority of affected people can identify triggers that may precede an attack.
Diagnosis
One of, if not the most common form of organic acidemia, methylmalonic acidemia is not apparent at birth as symptoms usually do not present themselves until proteins are added to the infants diet. Because of this, symptoms typically manifest anytime within the first year of life. Due to the severity and rapidity in which this disorder can cause complications when left undiagnosed, screening for methylmalonic acidemia is often included in the newborn screening exam.Because of the inability to properly break down amino acids completely, the byproduct of protein digestion, the compound methylmalonic acid, is found in a disproportionate concentration in the blood and urine of those afflicted. These abnormal levels are used as the main diagnostic criteria for diagnosing the disorder. This disorder is typically determined through the use of a urine analysis or blood panel. The presence of methylmalonic acidemia can also be suspected through the use of a CT or MRI scan or ammonia test, however these tests are by no means specific and require clinical and metabolic/correlation. Elevated levels of ammonia, glycine, and ketone bodies may also be present in the blood and urine. Types
Methylmalonic acidemia has varying diagnoses, treatment requirements and prognoses, which are determined by the specific genetic mutation causing the inherited form of the disorder.