Epilepsy, brain swelling may be first symptoms of AIP: Case report
Man also experienced episodes of unconsciousness, abdominal pain
In rare cases, epilepsy and posterior reversible encephalopathy syndrome (PRES), a condition marked by brain swelling that leads to seizures, headaches, and confusion, may be the first signs of acute intermittent porphyria (AIP), according to a case report.
“This case highlights the heterogeneous [varied] neurological manifestations of AIP, particularly the rare presentation of epilepsy as the initial symptom combined with PRES,” researchers wrote.
The report, “Acute Intermittent Porphyria With Epilepsy as the Initial Symptom and Posterior Reversible Encephalopathy Syndrome: A Case Report,” was published in the journal Case Reports in Neurological Medicine.
AIP symptoms often appear suddenly
Porphyria encompasses a group of genetic disorders marked by a deficiency in one or more enzymes needed for the production of heme, the iron-containing compound essential for transporting oxygen in the body.
AIP is caused by mutations in the HMBS gene, leading to reduced activity of the enzyme porphobilinogen deaminase, which is responsible for the third step in the heme synthesis pathway. When this enzyme is deficient, intermediate compounds known as porphyrin precursors accumulate to harmful levels, particularly affecting the nervous system.
Symptoms of AIP often appear suddenly and may last for several days to weeks before gradually lessening. Attacks typically involve intense abdominal pain and may be accompanied by gastrointestinal disturbances such as nausea, vomiting, constipation, or diarrhea. Other notable signs include dark or reddish urine and urinary difficulties during acute episodes.
Neurological symptoms may also occur, including nerve pain or weakness in the arms and legs, as well as seizures, which can manifest as sudden shaking, twitching, or brief loss of consciousness. Muscle weakness or wasting, especially in the shoulders and upper arms, can also develop over time. In rare cases, confusion, hallucinations, or other mental health changes may occur during severe attacks.
Patient lost significant amount of weight
Here, researchers in China reported the case of a 28-year-old man with AIP who initially developed epileptic seizures and PRES — an uncommon brain condition marked by temporary swelling and abnormal signals on MRI scans – as first symptoms.
Fifteen days before being admitted to the hospital, the patient had experienced episodes of unconsciousness and limb twitching, which coincided with daily episodes of abdominal pain.
He had been experiencing intermittent abdominal pain for about three months before admission, with episodes occurring several times per week and lasting a few hours each. About a month after the pain began, he developed worsening muscle weakness, mainly in his upper arms and shoulders. His symptoms worsened over time, and he became increasingly weak and fatigued. The patient had also lost significant weight, dropping from 80 kilograms (about 176.37 lbs) to 65 kilograms (about 143.3 lbs) over six months. Initial examinations revealed high blood pressure.
Physical examination revealed an emaciated appearance and visible muscle wasting in the shoulders. Neurological testing showed marked weakness in the upper limbs and mild weakness in the lower limbs, with reduced reflexes in the arms.
Further tests revealed impairments in the electrical signal from nerves to muscles, typical of nerve injury or degeneration. Nerve conduction tests showed a mild slowing of activity in nerves of the shoulders and upper arms.
MRI scans of the spine and brachial plexus – a network of nerves of the neck and upper spine that supplies movement and sensation to the shoulder, arm, and hand – were normal, ruling out structural causes of weakness.
Brain MRI showed abnormal signal changes consistent with PRES
Before his hospital admission, the patient underwent a brain MRI that showed abnormal signal changes consistent with PRES. At the time of this MRI, he was experiencing repeated episodes of unconsciousness along with limb twitching, daily abdominal pain, and significant muscle weakness in his upper arms.
Lab tests revealed below-normal levels of sodium in the blood, known as hyponatremia, and slightly elevated liver enzymes.
A follow-up MRI three weeks later showed that the brain abnormalities had resolved, with the patient experiencing no further seizures or abdominal pain.
Due to the unexplained abdominal pain, neurological symptoms, and seizures — and when other possible causes had been ruled out — physicians suspected AIP. As a result, they exposed the patient’s urine to sunlight, and it turned a wine-red color, a classic sign of porphyrin accumulation. Urine testing confirmed elevated porphobilinogen, and genetic analysis identified a mutation in the HMBS gene, confirming a diagnosis of AIP.
The patient received into-the-vein treatment with hemin to reduce porphyrin precursor levels. Also, he discontinued sodium valproate, a medication used to treat epilepsy but known to worsen AIP, and switched to levetiracetam for seizure control.
His treatment plan also included fluids to restore his body’s salt and mineral balance, as well as a high-carbohydrate diet.
One month after treatment, the patient’s weight increased, his muscle strength improved, and he had no recurrence of seizures or abdominal pain. Two months later, his muscle strength had fully recovered, his weight had returned to normal, and he was able to resume normal work and daily activities.
Overall, “this case is clinically meaningful and unique,” the researchers wrote, adding that it “underscores the importance of considering AIP” when a patient shows “epilepsy with unexplained abdominal pain,” they concluded.
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