Lyme Meningitis Leading to Hyponatremia and SIADH
Lyme meningitis may rarely present with hyponatremia and SIADH
Neurologic symptoms can precede diagnosis by weeks
Treatment of the infection may reverse both conditions
There are many causes of hyponatremia. Any disorder of the central nervous system, including infections, can trigger it. However, only a few case reports of Lyme meningitis or Lyme neuroborreliosis have been published with a focus on hyponatremia, according to the authors.
Lyme neuroborreliosis refers to nervous system involvement from Lyme disease and may include meningitis, radiculitis, cranial neuropathies, and other neurologic manifestations.
Hyponatremia is a condition that occurs when the level of sodium in the blood is too low. With this condition, the body holds onto too much water. This dilutes the amount of sodium in the blood and causes levels to be low.
One month prior to being admitted to the hospital, the 83-year-old woman had presented to the emergency department because of stabbing back pain localized to the left shoulder.
Shoulder Pain and Neurologic Symptoms Preceded the Diagnosis
“The shoulder pain gradually subsided but lower back pain ensued, worsening at night,” wrote the authors. “In parallel, she noticed difficulties in concentrating, unsteadiness, and poor appetite.”
The woman was admitted for an evaluation of nonspecific gastrointestinal symptoms and weight loss.
Her sodium was low (hyponatremia 125 mmol/L), consistent with Syndrome of Inappropriate Antidiuretic Hormone (SIADH) secretion.
The doctors could not find a cause. Drug-related hyponatremia was suspected in the absence of another diagnosis, and her blood pressure medication was changed.
The antihypertensive was held. As sodium levels were slightly higher when controlled 5 days later, amlodipine was prescribed instead.
However, a month later, her sodium levels were still low (126 mmol/L).
“In view of the history, nocturnal back pain and obscure hyponatremia, she was admitted for a lumbar puncture,” wrote the authors.
Lyme Meningitis Was Identified After Lumbar Puncture
Her spinal tap was diagnostic for Lyme meningitis.
SIADH resolved after a 3-week course of antibiotics.
In hindsight, the lancinating shoulder pain prompting the patient’s first hospital visit likely represented Bannwarth syndrome, a radiculoneuritis occurring early in the course of Lyme disease, the authors pointed out.
This case illustrates how neurologic Lyme disease can present with symptoms extending beyond the nervous system. Lyme meningitis and related neurologic manifestations may occasionally be associated with metabolic abnormalities such as hyponatremia.
Patients with Lyme disease may also experience autonomic symptoms involving blood pressure regulation, dizziness, and other neurologic complaints, which are discussed in autonomic dysfunction and Lyme disease.
Frequently Asked Questions
Can Lyme disease cause hyponatremia?
Hyponatremia is uncommon in Lyme disease but has been reported in cases of Lyme meningitis and Lyme neuroborreliosis. The mechanism may involve SIADH triggered by central nervous system infection.
What is SIADH?
Syndrome of Inappropriate Antidiuretic Hormone (SIADH) secretion occurs when excessive antidiuretic hormone causes the body to retain water, resulting in dilution of sodium levels in the blood.
Can Lyme meningitis lead to SIADH?
Although uncommon, case reports have described SIADH occurring in patients with Lyme meningitis and resolving after treatment of the underlying infection.
What is Bannwarth syndrome?
Bannwarth syndrome is a form of Lyme neuroborreliosis characterized by severe radicular pain, neurologic symptoms, and cerebrospinal fluid abnormalities.
What are symptoms of Lyme meningitis?
Symptoms may include headache, neck stiffness, cognitive difficulties, radicular pain, balance problems, fatigue, and other neurologic complaints.
Clinical Takeaway
Hyponatremia and SIADH are uncommon but potentially important manifestations of Lyme neuroborreliosis. In patients with unexplained hyponatremia accompanied by neurologic symptoms, Lyme meningitis may warrant consideration in the differential diagnosis.
Persistent hyponatremia without a clear explanation should prompt consideration of underlying neurologic disorders, including Lyme neuroborreliosis in appropriate clinical settings.
This case highlights how Lyme meningitis can present with both neurologic and metabolic abnormalities, with resolution following appropriate antibiotic treatment.
Related Articles
Neurologic Lyme disease
Lyme disease causes a mix of symptoms, including autonomic dysfunction
Meningitis and radiculitis due to Lyme disease
Lyme meningitis manifesting as parkinsonism
References
- Windpessl M, Oel D, Muller P. A Tick-Borne Cause of Hyponatremia: SIADH Due to Lyme Meningitis. Am J Med. 2022. doi:10.1016/j.amjmed.2022.05.013.
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
Hello Dr. Cameron. I am an old patient Dr. Glenn Askedall disabled for years with chronic lyme or bartonella. A strange thing happened to me. I had to go for an mri of my prostate which turned out to be a small cancerous tumor which is now gone with the proton therapy I received. The reason for this post is that when I went for the mri the nurses could not get an iv started. I suffer from what I think is hypovolemia. After the fourth jab they got an IV and gave me a bag of ringers solution. For the next two days I felt absolutely great! About 99% of my symptoms were gone for two days. I have not felt well since this IV last summer. I wish I could receive this IV again!!