Friday, May 23, 2008

Rosai-Dorfman disease presenting with widespread intracranial and spinal involvement

Kidd DP, Revesa T, Miller NR. Neurology 2006; 67:1551-1555.
Disease is also known as sinus histiocytosis with masssive lymphadenopathy. It has a much more benign prognosis than histiocytosis X. A registry published in 1990 of 238 patients showed that of 238 patients, 49 had a lasting remission, 165 had stable disease not requiring treatment, and 21 had died 4 of the disease. It presents in the third to fifth decade with cervical lymphadenopathy often preceded by a viral infection, with elevated ESR and polyclonal gammopathy. Steroids and/or XRT is used for treatment. Authors present two neurologic cases. One mimicked a sellar meningioma with loss of vision, hearing and smell. A gallium scan and chest CT showed chest lesions. The other presented with four months of progressive visual loss. Only 4 % have neurologic involvement (8 patients) five with spinal dural based lesions, three with intracranial epidural lesions.

My question: cases did not describe cervical adenopathy so why was diagnosis made?

Wednesday, May 14, 2008

Unusual sources of lead leading to intoxication

Lead was an ingredient of antibacterial ointments until the 20th century and are still sold in rural Switzerland. Traditional remedies including Asian plant products may be contaminated. Beauty ointments may be a culprit including lip balms (Fluri et al. Neurology 69:929 2007).

Serum, not urine lead levels should be checked and porphoryns may be elevated. MRI may show hyperintensity in the basal ganglia. Encephalopathy and motor neuropathy both can occur in adult intoxications.

Bacterial and fungal meningitis in patients with cancer

Safdieh JE, Mead PA, Sepkowitz KA et al. Neurology 2008; 943-947. High points-- only five percent of cases had the triad of fever, nuchal rigidity and mental status changes. VP shunt patients usually presented with mental status changes. Most patients had had prior neurosurgery. organisms included more gram positive infections and a smattering of diverse other organisms. CSF response was often muted.

Monday, May 12, 2008

Differential diagnosis of cervical radiculopathy

1) Peripheral nerve entrapment (eg CTS)- see positive Phalen's and Tinel's sign, typical distribution, abnormal nerve conduction studies v. normal in cervical radiculopathy

2)Rotator cuff abnormal-- pain in shoulder or arm, rarely below elbow, worse with shoulder movements, normal sensation and reflexes.

3) Acute brachial plexitis-- (Parsonage Turner)-- see pain in neck shoulder and arm followed within days to weeks by weakness especially in C5-6 region as pain recedes (whereas in radiculopathy pain and weakness coincide).

4) Thoracic outlet syndrome-- Pain in shoulder and arm, intermittent paresthesia, C8-T1 symptoms (rare in radiculopathy), reproduction with provocative tests including Roo's test (rapid flexion and extension of fingers with arms abducted at 90 degrees and externally rotated 90 degrees), normal neuro exam, decreased radial pulse with vascular compression (rare) and usually normal NCS.

5) Herpes zoster-- neuropathic pain in dermatomal distribution followed by vesicular rash.

6) Pancoast syndrome-- Pain in shoulder/arm due to plexus compression, paresthesia is in C8-T1 distribution (intrinsic hand muscles), ipsilateral ptosis, miosis, and anhidrosis.

7) Sympathetic mediated syndromes-- pain and burning in arm with swelling, hyperesthesisa, allodynia, and vasomotor changes (temperature and color) with normal neurologic examination.

8) Referred somatic pain from neck-- such as discs, joints, usually segmental C5-6 felt in posterior neck and supraspinatus fossa, normal neuro exam.

9) SUNCT/SUNA syndromes with pain in cervical region

Cervical radiculopathy

Carette S, Phil M, Fehlings MG. Clinical practice. NEJM 2005; 353:392-399.

The etiology in 70-75% is encroachment of the foramen due to cervical spondylosis or other cause of degeneration, whereas HNP is much less frequent (20-25 %) and tumors and other causes even less frequent. Pain occurs only if the dorsal root ganglion (DRG) is compressed. Hypoxia of the nerve root and DRG exacerbates the pain. Inflammatory mediators including MMP's, PGE2, IL6 and NO. Nonsurgical management resolution correlates with imaging improvement.

Neck and arm pain predominate. Sensory symptoms (burning, tingling) follow a dermatomal distribution, but pain follows a myotomal pattern. C7 pain for example includes radicular pain to forearm, and N/T to the third digit. Pain is relieved by looking to opposite contralateral side and holding hand on top of the hand and exacerbated by turning the head towards the pain. Red flags including systemic signs of illness (fever, chills, weight loss), diffuse hand numbness attributed to CTS, clumsiness, urinary urgency or frequency not retention or incontinence. Provocative tests for radiculopathy are mostly unreliable. C7 is most commonly affected followed by C6.

Signs of C5 involvement include pain in the medial scapular border radiating to the elbow, weakness of the deltoid, supraspinatus and infraspinatus, sensory loss in the lateral arm, and loss of the supinator reflex.Signs of C6 involvement include pain in lateral forearm, thumb and index finger, weak biceps, b-r, and wrist extensors, thumb and index finger sensory loss and loss of biceps reflex.

Signs of C7 involvement ae pain in medial scapula, posterior arm, dorsum of forearm, third finger, weak triceps, wrist flexors, finger extesnors, sensory loss in posterior forear and third finger, and loss of triceps reflex.

Signs of C8 involvementare pain in shoulder, ular side of forearm, fifth finger, weak thumb flexors, abductors, and intrinsic hand muscles,and sensory loss of the fifth finger.

Treatment is not proved in large trials. Analgesics including opiates and NSIAA's are first line sometimes with prednisone. Epidural injections result in relief that is longstanding in many patients but complications include spinal cord and brainstem infarction. Hard/soft cervical collar for short term or cervical pillow at night are used. Cervical traction is unproved. Exercise therapy including active AROM, aerobic conditioning with isometric and progressive resistive exercises are usually recommended after initial period.

Indications for surgery include cervical root compression on imaging, concordant pain or dysfunction, persisting pain, or functional motor deficit, or compression of the cord. Anterior decompression with strut reconstruction is common.

Clinical feature and prognostic factors in adults with bacterial meningitis

van de Beek B, de Gans J, Spanjaard L et al. NEJM 2004; 351: 1849-59. Dutch study analysed 696 cases of community acquired acute bacterial meningitis seen 1998-2002. The classic triad of neck stiffness, fever, and change of mental status was seen in only 44 %, but 95 % had two of the four symptoms (the fourth symptom being headache). Mortality was 21 % and much higher with pc meningitis than mc meningitis (30 v. 7 %). Risk factors (negative risk) were advanced age, present otitis or sinusitis, absent rash, low GCS on admission, tachycardia, positive blood culture, elevated sed rate, thrombocytopenia, and low CSF WBC. Worst risk thus was with systemic compromise, low level of consciousness and infection with SC.

In more detail, HA occurred in 83 %, fever in 77 %, change in mental status in 69 % (GCS <14). Rash was present in 26 % and usually indicated mc infection (98 % of time) . 89 % of rashes were petechial. Only 3 % of those with information had papilledema.

Discussion of steroids: The european dexamethasone study showed adjunctive treatment with corticosteroids was beneficial although a posthoc analysis showed it to be more likely due to reduction in systemic than neurologic complications.

HABC Hypomyelination of basal ganglia nad cerebellum

van der Kmaap MS, Linnannkivi T, Paetau A et al. Hypomyelination with atrophy of the basal ganglia and cerebellum: followup and pathology. Neurology 2007; 69: 166-171.

A report of 11 new patients is made. Typically a pediatric population presented with normal or delayed psychomotor development, with increasing extrapyramidal movement disorders, spasticity and ataxia. The putamen was small or absent, the caudate often atrophic with normal thalamus and globus pallidus. The cerebellar granular layer was typically affected. All known patients were sporadic. This is a recently described syndrome (2002) with less than 20 reported cases.