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Q1: What is the likely diagnosis and what supportive investigations would be helpful?
The magnetic resonance scan (see p 531) shows increased signal intensity in the cervical cord which enhanced after intravenous contrast. The liver biopsy specimen (see p 531) shows a non-caseating granuloma with formation of multinucleate giant cells. Although not specific, these changes in the context of the history and other positive investigations were highly suggestive of neurosarcoidosis.
Supportive biochemistry includes a raised serum calcium and angiotensin converting enzyme (ACE). Cerebrospinal fluid analysis revealing oligoclonal bands would also support the diagnosis. Our patient's serum calcium was 2.65 mmol/l, her ACE was 185 IU/l (normal 10–75), and she had oligoclonal bands on cerebrospinal fluid analysis.
Q2: What further test should be performed to help guide management?
Pulmonary function tests should be performed to assess extent of functional lung involvement, although it is unusual to have abnormal lung function in the absence of radiographic changes. Ninety per cent of patients with sarcoid have involvement of the respiratory system and so require baseline documentation of function. Respiratory manifestations can vary from asymptomatic bilateral hilar lymphadenopathy to severe pulmonary fibrosis and marked restrictive defects on pulmonary function testing. It is not unusual for some patients to present with a mixed obstructive and restrictive picture. This could occur for instance with lymph node obstruction of a large airway as well as parenchymal disease.
Neurological presentation occurs in approximately 5% to 16% of patients with sarcoidosis.1 Seventh nerve involvement is the most common presenting neurological feature and mononeuritis multiplex as illustrated by this case is not uncommon. Sarcoidosis presenting with pancreatitis, however, is rare.
Hilar lymphadenopathy is the most common abnormality on chest radiography in sarcoidosis. In some cases, however, this may only be obvious on computed tomography of the chest.2 High resolution computed tomograms are useful in the evaluation of diffuse infiltrative lung disease in which case they have been shown to be superior to conventional radiography.3
Hypercalcaemia is another feature and is due to the 1α-hydroxylation of vitamin D3 that occurs within the macrophages of the granulomas. It occurs in about 10% of patients.4 A raised ACE level occurs in almost two thirds of patients. Its place in diagnosis is debatable, as raised levels may occur in many other diseases including asbestosis, silicosis, berylliosis, fungal infection, granulomatous hepatitis, hypersensitivity pneumonitis, leprosy, lymphoma, and tuberculosis. However serial measurements are useful for monitoring disease activity and response to treatment. Liver involvement with microscopic, non-caseating granulomas is common and biopsy will reveal granuloma in almost 90% of cases. However, studies have shown white people to have a lower yield of granulomas on biopsy and this should be borne in mind by attending physicians.5
Sarcoidosis is a multisystemic illness and may affect any part of the body. Stage I pulmonary disease, that is hilar and mediastinal lymph node enlargement alone, usually remits spontaneously and has not been shown to benefit from steroid therapy. Early treatment with systemic corticosteroid (for example prednisolone 1 mg/kg/day initially) is warranted in extrapulmonary disease, such as in our case where there was a danger of irreversible neurological and ocular damage. Treatment once started is continued for several months and tailed down once markers of disease activity improve. Other agents that have successfully been tried in the long term management of refractory neurosarcoidosis include methotrexate and cyclophosphamide.1
A diagnosis of neurosarcoidosis with pancreatic and liver involvement was made and our patient was started on prednisolone 60 mg daily. She made remarkably good progress and was well enough to be discharged two weeks later. At follow up after four weeks, there had been complete resolution of the facial nerve weakness and the only residual neurology was mild paraesthesia over the left knee.
Neurosarcoidosis with pancreatic and liver involvement.