Recurrent Stroke-Like Symptoms, Abnormal Brain MRI Findings May Signal CMTX1 in Women, Case Report Says
X-Linked Charcot-Marie-Tooth Type 1 (CMTX1) should be considered in the differential diagnosis of women experiencing recurring stroke-like symptoms, such as slurred speech and limb weakness, and showing abnormal findings in brain magnetic resonance imaging (MRI) scans, according to a case report.
The study, “Recurrent Stroke-Like Symptoms After Cesarean Section Deliveries in a Female Patient With X-Linked Charcot-Marie-Tooth Type 1,” was published in the journal Frontiers in Neurology.
CMTX1, the second most common type of Charcot-Marie-Tooth (CMT) disease, is caused by mutations in a gene located on the X chromosome, GJB1, which provides instructions to make a protein called connexin 32.
In addition to typical CMT symptoms involving the peripheral nervous system, patients with CMTX1 also have central nervous system (CNS) abnormalities. The peripheral nervous system is the network of nerves responsible for controlling movement and sensation in the limbs, while the CNS consists of the brain and spinal cord.
Because CMTX1 is an X-linked disease, men carrying a mutation in the GJB1 gene on their sole X chromosome typically start experiencing symptoms of the disorder immediately. Women who have two X chromosomes are less likely to have the disease.
Physicians described the rare case of a woman with CMTX1 who experienced stroke-like symptoms.
The 29-year-old woman arrived at the hospital complaining of “recurrent slurred speech and right limb weakness for [one] day,” the case report said.
A day prior to admission, she said, she woke up and was suddenly unable to speak clearly and started having difficulty walking due to weakness in her right leg. Although the symptoms disappeared within three hours, they returned three times.
Physicians reviewing her medical history found she had given birth to her second child via caesarean section under anesthesia 21 days earlier.
They also found that about half a month after giving birth to her first child seven years before, she experienced the same stroke-like symptoms that recurred approximately three times, then improved quickly and completely.
Doctors at the time performed a brain computed tomography (CT) scan, which came back normal. However, they did not order a brain MRI.
A brain MRI showed abnormal signals in different structures of the brain, including the corpus callosum, posterior limbs of bilateral internal capsule, and centrum semiovale. The corpus callosum is the region that connects the left and right sides of the brain; the internal capsule is the region where motor neurons that control the movements of the arms, trunk and legs and sensory fibers are located; and the centrum semiovale is a mass of white matter (regions of the brain made up of nerve segments responsible for the transmission of nerve signals) found in both sides of the brain.
An electromyogram, a test used to record the electrical activity of muscles, showed the woman had sensorimotor peripheral neuropathy, a condition in which the nerves found outside the CNS that control sensation and movement become damaged, which is a hallmark of CMT.
Although her main symptoms were associated with a dysfunction of the CNS, the woman also had typical CMT symptoms, including pes cavus (a foot deformity characterized by an abnormally high arch), and peripheral neuropathy.
“Although she had no definite family history [of the disease], we still suspected the possibility of CMTX1,” the physicians said.
To confirm their suspicions, physicians ordered a genetic test. Gene sequencing revealed the presence of a mutation (C.622G>A; p.Glu208Lys) in the GJB1 gene, confirming the diagnosis of CMTX1.
“The diagnosis of CMTX1 should be considered, even in female patients, when the disease presents with recurrent stroke-like symptoms and abnormal white matter signals on MRI,” the physicians said.
They also noted that each of her episodes occurred just after undergoing a caesarean section, which had never been reported in the past. Hormonal changes occurring post-partum, including the abrupt reduction of estrogen and progesterone, could lead to the development of these recurrent stroke-like symptoms, they said.
“Further functional studies are required to verify the hypothesis and explore the underlying biological mechanism,” they said.