SSRI Withdrawal Syndrome
Karen is a 38 year old new mother (baby girl 8 months) who came to me with unusual symptoms that were of concern. She began having "episodes" of a buzzing, electrical feeling in her head and neck. It felt like a "shock" in her head. At times she would feel so dizzy and off balance that she had to pull over in the car or sit down. There was no headache but she felt some numb patches on her arms and legs. There was a vague depersonalization that accompanied the spells. It would happen for several days, then disappear for weeks and then come back. The "spells" lasted a few minutes to hours but seemed to be increasing over the past week.
When patients present with strange symptoms like this, a doctor has to start at the beginning with a detailed history. Any new medications? Any over the counter medications? Any drugs or alcohol? Any visual changes or blurry vision? The answer to all of these questions was no.
The work up progressed with blood tests looking for Vit B 12 deficiency, thyroid dysfunction, infection. When these returned normal and the symptoms persisted, more testing was needed.
Unusual symptoms like this in a young woman could be a sign of an autoimmune disease that affects the myelin sheath around nerves, such as Multiple sclerosis. In MS the episodes can wax and wane, just like Karen's did. She felt worse when it was hot and MS episodes can be triggered by heat. I was quite concerned that it could be MS, but we were reassured when an MRI of the head and spine returned normal.
Luckily, the symptoms disappeared again. Imagine my surprise two months later when the mystery was solved. Karen had been prescribed Zoloft, a SSRI medication for post-partum depression. She started on a low dose and when that didn't work, her OB doctor told her to increase it. Instead of getting a new prescription, she just doubled the dose and ran out of the drug after two weeks. She would fill the prescription the next month and run out again and again. She was starting and stopping an SSRI medication, getting no good effect, but triggering classic SSRI withdrawal syndrome each time she stopped.
Zoloft is a short acting SSRI. That means they are cleared from the body quickly when discontinued. If the dose is abruptly discontinued there is a rebound that blocks the neurotransmitter, Acetylcholine. It can also cause an excitability in the brain that is not well understood.
When Karen was asked if she was taking any new medication she honestly said "no" because she had stopped the Zoloft and didn't realize the importance of her "on and off" regimen. That one key clue would have solved the mysterious diagnosis months earlier.
When she started taking the proper dose of Zoloft continually, her depression lifted, her "shock waves" and dizziness resolved and it was a good lesson for both doctor and patient.