The Dilemma, Conversion Disorder or Stiff Person Syndrome, a Case Report

Abstract

Study Objectives

The main objectives of this case study are 1. Clinicians facing symptoms that are difficult to interpret should exercise caution in diagnosing conversion disorder. 2. Increasing awareness about rare neurological conditions may appear as psychogenic illnesses. 3. Clinicians be advocate for their patients.

Introduction

Conversion disorder is a mental condition in which a person present with one or more symptoms of altered voluntary motor or sensory function, or other neurologic symptoms that cannot be explained by medical evaluation. Stiff person syndrome (SPS) is a disabling autoimmune central nervous system disorder characterized by progressive muscle rigidity, gait impairment, with superimposed painful spasms. SPS is commonly associated with high anti-glutamic acid decarboxylase (GAD) antibody titers. The dominant antigen recognized by these antibodies is the GABA-synthesizing enzyme GAD.

Method

Patient X, a 17-year-old Hispanic American female who presented to the Child and Adolescent Psychiatry Clinic with the complaint of ataxia & aphasia associated with anxiety. Patient was referred by the neurology clinic after they could not establish any organic cause of her ataxia or aphasia. After thorough evaluation at the child psychiatry clinic she was given the diagnosis of anxiety secondary to ataxia and aphasia and r/o Conversion Disorder. She was initiated treatment with sertraline for her anxiety. Her sertraline dose was increased gradually up to 100 mg daily. From the beginning the patient also received counseling & physical therapy. With these combination of treatments, patient’s symptoms did not get any better. Her symptoms actually got worse over time. At this point, the Child Psychiatry Clinic sent a message to the neurology clinic for further evaluation of patient due to her progressive gait and speech impairments.

Results

The neurology clinic saw the patient again and did further testing. The patient was positive for high titers of anti-glutamic acid decarboxylase antibodies (Anti-GAD). At this point, the patient was given the diagnosis of Stiff Person Syndrome. Patient was admitted to the hospital for further management. She was treated with benzodiazepines, IV immune globulin, & steroid. Soon after discharge from the hospital, the patient was seen at the Child Psychiatric Clinic. The patient’s mother reported, after the in-patient treatment, the patient’s symptoms improved.

Discussion

It is essential for clinicians to look for neurologic & other general medical conditions while evaluating a patient with possible conversion disorder. A systematic review of 27 studies found that among 1466 patients initially diagnosed with conversion symptoms, the frequency of misdiagnosis was approximately 4 percent.

References. BMJ. 2005;331(7523):989. Epub Oct 13. Childhood onset of stiff-man syndrome. JAMA Neurol. 2013;70(12):1531. J Neurol Neurosurg Psychiatry. 2015 Aug; 86(8):840–8. Epub 2014 Dec 15.