Strep, or Streptococcus, refers to bacteria that commonly cause infections like strep throat. While direct brain invasion by strep is rare, neurological complications can arise indirectly. These complications stem from the body’s immune response, not from bacteria physically entering the brain. Understanding these indirect effects is important for recognizing potential health concerns.
The Blood-Brain Barrier and Direct Infection
The brain is protected by a specialized structure called the blood-brain barrier (BBB). This barrier is a highly selective semipermeable membrane that regulates the passage of substances from the bloodstream into brain tissue, effectively shielding the central nervous system from pathogens.
Due to the blood-brain barrier’s effectiveness, direct bacterial infections of the brain, such as meningitis, are uncommon from typical strep throat. While severe, invasive Streptococcus infections can rarely lead to bacterial meningitis, this is not the typical progression from common strep throat.
Strep-Related Neurological Conditions
Neurological issues linked to strep infections typically arise from an autoimmune response, where the body’s immune system mistakenly attacks its own tissues, including parts of the brain. This occurs because certain components of the strep bacteria resemble molecules found in the body’s own cells, leading to a misdirected immune attack. Two specific conditions exemplify this indirect mechanism: Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS) and Sydenham’s Chorea.
PANDAS
PANDAS is a syndrome thought to affect some children following strep infections. In PANDAS, the immune system produces antibodies that cross-react with and target specific areas of the brain, particularly the basal ganglia. This part of the brain plays a role in controlling movement, emotions, and behavior. The onset of symptoms in PANDAS is often sudden, appearing rapidly after a strep infection.
Sydenham’s Chorea
Sydenham’s Chorea is another neurological disorder that occurs as a complication of Group A beta-hemolytic Streptococcus infection. It is an autoimmune disease where the immune system’s response to the strep infection affects the nervous system. Sydenham’s Chorea is a manifestation of acute rheumatic fever, a serious inflammatory condition that can impact the heart, joints, skin, and brain. The condition is characterized by involuntary, jerky movements and can also present with emotional lability. It typically develops weeks to months after the initial strep infection.
Signs of Neurological Complications
Recognizing the signs of strep-related neurological complications is important, particularly because symptoms often appear suddenly.
PANDAS Symptoms
In PANDAS, children may experience a sudden onset of obsessive-compulsive disorder (OCD)-like symptoms or tics. These can include repetitive behaviors such as excessive handwashing or checking, as well as involuntary movements or sounds. Other behavioral changes might involve severe anxiety, separation anxiety, mood swings, irritability, or behavioral regression. Physical manifestations can also arise, such as changes in handwriting, difficulty concentrating, and new issues with bedwetting or sleep disturbances.
Sydenham’s Chorea Symptoms
For Sydenham’s Chorea, the most prominent symptom is chorea, which refers to rapid, uncoordinated, jerky movements. These involuntary movements often affect the face, hands, and feet. Individuals might also exhibit clumsiness, difficulty maintaining a hand grip, or a restless appearance. Beyond motor symptoms, Sydenham’s Chorea can lead to emotional lability, characterized by sudden mood swings. Speech difficulties, such as slurred speech, and challenges with concentration can also be observed.
Treating Strep to Prevent Complications
Prompt antibiotic treatment for strep throat helps prevent serious complications, including the indirect neurological ones. Antibiotics work by eliminating the Streptococcus bacteria, thereby reducing the risk of the body’s immune system initiating a misdirected attack.
For individuals who develop PANDAS or Sydenham’s Chorea, medical management often involves addressing the underlying strep infection with antibiotics. Symptomatic treatments are also used to manage the neurological and psychiatric manifestations. These can include medications such as anti-inflammatory drugs, or in some cases for Sydenham’s Chorea, anticonvulsants or antipsychotics to help control involuntary movements and behavioral symptoms. Continued medical follow-up and, for Sydenham’s Chorea, long-term antibiotic prophylaxis may be recommended to prevent recurrences.