On average, it takes seven years to receive a proper diagnosis. The differential diagnosis of PNES firstly involves ruling out epilepsy as the cause of the seizure episodes, along with other organic causes of non-epileptic seizures, including syncope, migraine, vertigo, anoxia, hypoglycemia, and stroke. However, 5–20% of people with PNES also have epilepsy. Frontal lobe seizures can be mistaken for PNES, though these tend to have shorter duration, stereotyped patterns of movements, and occurrence during sleep. Next, an exclusion of factitious disorder (a subconscious somatic symptom disorder, where seizures are caused by psychological reasons) and malingering (simulating seizures intentionally for conscious personal gain – such as monetary compensation or avoidance of criminal punishment) is conducted. Finally other psychiatric conditions that may superficially resemble seizures are eliminated, including panic disorder, schizophrenia, and depersonalisation disorder.The most definitive test to distinguish epilepsy from PNES is long term video-EEG monitoring, with the aim of capturing one or two episodes on both video recording and EEG simultaneously (some clinicians may use suggestion to attempt to trigger an episode). Additional clinical criteria are usually considered in addition to video-EEG monitoring when diagnosing PNES. By recording the event in question on video and EEG simultaneously, a clear diagnosis can usually be obtained.Laboratory testing can detect rising blood levels of serum prolactin if samples are taken in the right time window after most tonic-clonic or complex partial epileptic seizures. However, due to false positives and variability in results, this test is relied upon less frequently.
Diagnosis
The diagnosis is based on the biochemical findings (increased concentrations of lysine, arginine and ornithine in urine and low concentrations of these amino acids in plasma, elevation of urinary orotic acid excretion after protein-rich meals, and inappropriately high concentrations of serum ferritin and lactate dehydrogenase isoenzymes) and the screening of known mutations of the causative gene from a DNA sample. Treatment
Treatment of LPI consists of protein-restricted diet and supplementation with oral *GeneReview/NIH/UW entry on Lysinuric Protein Intolerance citrulline. Citrulline is a neutral amino acid that improves the function of the urea cycle and allows sufficient protein intake without hyperammonemia. Prognosis
Under proper dietary control and supplementation, the majority of the LPI patients are able to have a nearly normal life. However, severe complications including pulmonary alveolar proteinosis and chronic kidney disease may develop even with proper treatment.Fertility appears to be normal in women, but mothers with LPI have an increased risk for complications during pregnancy and delivery. References
External links
GeneReview/NIH/UW entry on Lysinuric Protein Intolerance