Sarcoidosis has many presentations with neurosarcoidosis being a rare manifestation. Cauda equina sarcoidosis is distinctly rare with only twenty reported cases. We present a case of acute cauda equina syndrome that was determined to be a de novo presentation of sarcoidosis.
A previously healthy 55 year old female presented to a peripheral hospital after waking up with back pain, bilateral sciatica, leg weakness and parasthesia. She subsequently developed rapid proximal neurological progression with incontinence, flaccid paralysis and areflexia. Urgent bloodwork and magnetic resonance imaging (MRI) were normal. Examination of two cerebrospinal fluid (CSF) collections showed elevated white blood cells and protein but cultures and cytology were negative. Empiric treatment for Guillain Barre Syndrome (GBS) was ineffective and a repeat MRI with gadolinium found an expanding conus medullaris lesion with linear spinal cord enhancement. Computed tomography (CT) of the chest also found a spiculated right lower lobe (RLL) nodule and mediastinal lymphadenopathy. The patient was transferred to our hospital for evaluation of persistent cauda equina syndrome. She denied any dyspnea, cough or hemoptysis and had no significant social, family, occupational or exposure history. Physical examination showed no clubbing or respiratory findings. Electrodiagnostic testing was inconsistent with GBS. Bronchoalveolar lavage (BAL), transbronchial biopsy and trans-esophageal lymph node aspirate were all nondiagnostic. Intravenous steroids for seven days improved her neurological function and she declined further testing before being discharged for rehabilitation. Outpatient follow-up of her lung nodule and lymphadenopathy prompted positron emission tomography (PET) scanning. Increased glucose metabolism in the RLL nodule, right pretracheal and subcarinal areas were consistent with a stage 3A lung carcinoma. Repeat CT showed growth of the right pretracheal lymph node which was sampled via mediastinoscopy. It showed extensive noncaseating graulomatous inflammation with no malignant cells. Fungal and mycobacterial stains were also negative. Sustained steroid therapy resulted in marked neurological improvement and repeat CT demonstrated resolution of the RLL nodule and lymphadenopathy.
Sarcoidosis that presents in the cauda equina and conus medullaris is very rare and difficult to diagnose. Its presentation is usually subacute or chronically progressive pain and weakness in the legs. Needle electromyogram shows acute denervation in the lower limbs. CSF shows non-specific total protein elevation and lymphocytic pleocytosis. CSF angiotensin-converting enzyme (ACE) elevation has also been described. Despite the high sensitivity of MRI with or without gadolinium, some patients have normal neuroimaging. Neural tissue biopsy has confirmed the diagnosis in the majority of cases but whole body gallium and PET scans have successfully found other sites for biopsy. In patients presenting with neurosarcoidosis, the role of serum ACE levels is limited and the value of BAL has not been established. Cauda equina sarcoidosis is usually a diagnosis of exclusion based on the combination of clinical, radiographic and histological findings. Neurological symptoms usually respond to steroid therapy but high maintenance doses may be needed to prevent recurrence of disease.This case highlights the diagnostic approach when evaluating a patient with a pulmonary nodule and neurological symptoms. It represents the first case to describe sarcoidosis presenting as acute cauda equina syndrome. It is also the first case of cauda equina sarcoidosis to have either a solitary pulmonary nodule or PET scan for evaluation.
Sarcoidosis can present as acute cauda equina syndrome and should be included in its differential diagnosis. PET scan can be used in suspected cauda equina sarcoidosis to locate extra-neural sites for biopsy.
Aaron Aggarwal, No Financial Disclosure Information; No Product/Research Disclosure Information