Edinburgh 38Th Advanced Neurology Course 2016

Edinburgh 38Th Advanced Neurology Course 2016

Edinburgh 38th Advanced Neurology Course 2016

Clinicopathological case

In 2010, a male aged 53 years presented with a 10 day history of polydipsia and polyuria. He was previously well and on no medication. His initial blood tests are below, leading to a diagnosis of Diabetes Insipidus. Further investigations revealed no cause (see imaging), but hypogonadotropic hypogonadism was uncovered. He was treated with desmopressin and testosterone injections, and followed up in the endocrine clinic; his biochemistry resolved to normal.

Initial investigations (2010)

  • Sodium: 148
  • Plasma osmolality 310
  • Urine osmolality 155
  • Other routine blood tests (FBC, ESR/CRP, liver function, glucose, HIV, hepatitis screen, syphilis, B12, thyroid, auto antibody screen) all negative or unremarkable
  • MR pituitary (April): Post contrast, entire pituitary enhanced. Infundibulum expanded measuring 3.9 mm with post contrast enhancement (see figure)
  • CT Chest/abdomen/pelvis: normal
  • Repeat MR pituitary after 2 months treatment: as before, right middle cerebral artery bifurcation aneurysm measuring 5 mm (poorly visible on previous imaging) identified. Infundibulum expanded to 5 mm
  • MR pituitary (Sept): Infundibulum now 3 mm, less enhancement
  • MR pituitary (June 2011): Less prominent infundibulum

Subsequent clinical course

In July 2012 he was referred to neurology with left facial numbness “as if being stroked”. It was not painful, and had been present for perhaps 2 years, evolving more recently which had precipitated referral. The examination was normal. A diagnosis of trigeminal neuropathy suggested, and relevant investigations requested (see below), following which a clinical diagnosis was suggested and it was decided to manage him conservatively.

Over the next year he was troubled by increasing general fatigue and left facial numbness. In May 2014 it was decided to treat him with oral prednisolone starting at 40 mg/day. There was a minimal response, and in July 2014 steroids were tapered and withdrawn.

Around this time a second neurological opinion was sought: fatigue was the main symptom, but the left facial numbness was a little worse, affecting the left side of his tongue and taste also. Referral to a specialist clinic was suggested.

In January 2015, a third neurologist was involved, who noted in addition to above a history of a bilateral slightly tender skin rash over lateral shins, dark red in colour, which had improved but not disappeared with steroids. Further investigations and opinions were requested.

  • Dermatology opinion: See skin biopsy result
  • Neuro-ophthalmic opinion (no symptoms): inferior left retinoschisis
  • Haematology opinion: Unlikely to be a primary haematological disease, bone marrow undertaken

In April 2015 he was deteriorating; his fatigue and facial numbness were much worse, and he complained of dizziness, unsteadiness and difficulty with focussing and thus admitted for more investigations and treated with IV methylprednisolone followed by oral steroids. There was a minimal response to this. He underwent diagnostic investigations.

Investigations 2013 and onwards

  • Jan 2013: MR head: High signal T2 lesions in both middle cerebellar peduncles up to 12 mm. Also left pons, punctate enhancement, and other areas of enhancement (right superior cerebellar peduncle, right anterior frontal lobe, right peritrigonal white matter). Bilateral MCA aneurysms
  • July 2013: MR head: White matter changes progressing
  • Dec 2013: MR head: slight interval progression with more T2 hyperintensity and enhancement particularly right cerebellar peduncle/pontine lesions
  • Nov 2014: MR head: further progression (figure)
  • Jan 2015: High resolution CT chest: non-specific apical pleural parenchymal fibrosis and minor pleural nodularity, unchanged from previous imaging 2010 (although not reported at the time). Healing fracture of left posterior 5th rib
  • March 2015: MR whole spine: Enhancing cord/intra-axial focus of high T2 signal at T4/5, low T2 signal enhancing nodule within right spinal canal/extra-axially at T12 (see figure)
  • March 2015: MR head: stable
  • March 2015: CT chest/abdo/pelvis: Sclerotic lesion of L2 vertebral body, suggestive of metastatic deposit. Not present on previous CT 2010 (see figure)
  • March 2015: CSF examination normal, no oligoclonal bands
  • April 2015: Whole body PET: high grade uptake in proximal sigmoid colon, probably reflecting diverticulitis. Nil else

Biopsies

  • March 2015: Skin biopsy: subacute spongiotic dermatitis with a superficial dermal chronic inflammatory cell infiltrate
  • April 2015: bone marrow: No evidence of marrow infiltration, slightly hypercellular reactive appearing marrow
  • April 2015: L2 bone biopsy: No evidence of marrow infiltration or malignancy
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