Consider this rare disorder in patients with rapid-onset neurologic symptoms
Ms. J, age 63, is admitted to Neurology with progressive dizziness and cognitive impairment. She had developed word-finding difficulties, weakness, memory problems, and an episode of arm shaking, which prompted referral for inpatient workup. Ms. J has a history of hypertension, palpitations, and diabetes mellitus.
Her neurologic examination is variable; some examiners find pronounced aphasia and right-sided weakness, whereas others document a nearly normal examination. Lumbar puncture (LP) shows normal cell count, glucose, protein, and negative Gram’s stain; MRI of the brain is normal. Enterovirus polymerase chain reaction, cryptococcal antigen, and Lyme antibody are negative. Electroencephalography (EEG) demonstrates diffuse slowing. The primary team requests psychiatric consultation to assess for conversion disorder.
Ms. J is cooperative with psychiatric evaluation. She denies current or past psychiatric symptomatology and does not meet criteria for major depression, dysthymia, adjustment disorder, anxiety disorder, psychosis, or mania. She denies personal or family history of suicidal or homicidal ideation, intent, or plan. Her youngest son died 5 years earlier; she is financially secure and her 40-year marriage is stable. Ms. J denies having a history of substance use, physical or sexual abuse, or trauma.
In the Cardiology clinic 2 months ago, Ms. J denied having neurologic symptoms and was noted to be doing well. Her neurologic symptoms began shortly after that visit and steadily progressed. She is unable to identify an inciting event or stressor. Ms. J worked until 2 weeks before this admission. Neurologic examination at the time of psychiatric consultation is notable for waxing and waning expressive aphasia, right homonymous hemianopsia, and mildly decreased strength in the left biceps and forearm.
Ms. J presented to her cardiologist reporting dizziness and blurred vision 6 weeks ago, and she was observed in the hospital 3 weeks earlier for further evaluation. Laboratory testing during that hospitalization included blood counts, basic metabolic panel, thyroid function studies, erythrocyte sedimentation rate, thiamine, folic acid and vitamin B12, rapid plasma reagin and human immunodeficiency virus antibody, and LP, all reported as within normal limits.
Thorough review of Ms. J’s medical records reveals abnormalities that would be difficult to ascribe to conversion disorder. Specifically, 6 weeks ago, MRI of the brain demonstrated restricted diffusion in the left occipital lobe, and cerebrospinal fluid (CSF) neuron-specific enolase was moderately elevated at 34 ng/mL. The psychiatric consultant discusses these findings and concern for possible rapidly progressive dementia or Creutzfeldt-Jakob disease (CJD) with the primary team, Ms. J, and her family.
Ms. J is discharged with testing for CSF protein 14-3-3 pending and medical follow-up in 10 days. At follow-up 1 week later, her symptoms are worse; she is completely aphasic and wheelchair-bound. Antithyroglobulin and antimicrosomal thyroid antibodies and paraneoplastic antibody panel return normal. CSF protein 14-3-3 ultimately returns positive, supporting a clinical diagnosis of CJD. Ms. J dies shortly after hospital follow-up, less than 4 months after her first complaint of neurologic symptoms. No autopsy is performed.
Patients with conversion disorder may present with neurologic symptoms such as blindness, seizures, paralysis, or sensory loss with no identifiable anatomical or medical explanation.1 Conversion seizures—also known as pseudoseizures or nonepileptic seizures—may be clinically indistinguishable from generalized tonic-clonic seizures, but no EEG correlate can be identified.1,2 Conversion disorder is conceptualized as an unconscious manifestation of psychological conflict or stress—patients are not aware they are producing symptoms—and has been associated with emotional, sexual, and physical trauma.3,4
Conversion disorder is a diagnosis of exclusion and requires thorough evaluation to rule out neurologic or medical etiologies. The differential diagnosis for conversion disorder includes the broad medical differential diagnosis for the symptom, whether it be paralysis, seizures, sensory loss, or other presenting symptoms. Therefore, when evaluating patients for conversion disorder, be vigilant to the possibility of not only underlying psychological stress or trauma but also undiscovered medical or neurologic illness.
In Ms. J’s case, the primary team began to suspect there was no organic cause of her neurologic symptoms. However, psychiatric evaluation revealed that Ms. J had no history of stress or trauma that typically would be associated with conversion disorder, nor did she manifest other psychiatric symptoms, except waxing and waning mental status, which raised concerns for possible delirium or encephalopathy. Additionally, slowing on EEG was a nonspecific but abnormal finding that made conversion disorder unlikely. The consulting psychiatrist discussed this slowing, in conjunction with the abnormal MRI and elevated CSF neuron-specific enolase, with members of the referring Neurology service, who ordered additional testing of CSF for protein 14-3-3.