Thanks so much to our experts from the neurology department for coming to discuss a case of a 61 year old female without significant past medical history who presented with lower extremity weakness, progressive over several months, without associated sensory deficits. We broke our differential down by first thinking through the anatomy of the neuromuscular circuitry, which involves the upper motor neuron synapsing on the lower motor neuron, which interacts with the muscle cells through the neuromuscular junction. Here is a limited differential that we discussed:
This patient had both upper and lower motor neuron findings, and was diagnosed with ALS. Depending on location of affected nerves, presenting signs/symptoms of ALS may be weakness, fasciculations, atrophy similar to this patient. Patients can also present with hypercapnea due to diaphragm involvement, or bulbar signs such as slurring, dysphagia.
Currently, most of the treatment for ALS patients involves symptomatic management, as understanding of ALS pathophysiology and development of targeted interventions is still a topic of research. Riluzole is one medication that has been shown to have benefit in ALS patients, with quoted benefits of 2-3 month increase in survival and delaying respiratory failure. Interventions such as percutaneous endoscopic gastrostomy tubes and ventilator support are very personal decisions for patients and their families.
ALS patients benefit from a multidisciplinary care team, including physician specialists as well as respiratory therapists, occupational and physical therapists, social support team and others to provide best comprehensive care for themselves and their families.
Today’s case was a 47 yo F with congenital lymphangiectasia presenting with vertigo.
Obviously — the first thing we discussed was a quick review of congenital lymphangiectasia. It’s an exceedingly rare disease in which there are dilatation of intestinal lacteals resulting in lymph leakage into the small bowel. This disease is responsible for a protein-losing enteropathy leading to lymphopenia (CD4 count 36), hypoalbuminemia, and hypogammaglobulinemia.
Next we did a review of central vs. peripheral vertigo and how to differentiate between the two based on history and exam. While it’s not COMPLETELY black and white, the table below gives general guidelines to differentiate between the two.
Based on our patient’s presentation with vertical and horizontal nystagmus and positive skew deviation she was referred for MRI with c/f a central lesion.
Her MRI demonstrated multiple rim-enhancing brain lesions and we discussed the broad differential for an immunocompromised patient — including bacteria (abscess v. TB v. syphilis/gummas), fungal (crypto v. aspergillosis, v. histo v. coccidio v. actino v. mucor), Parasitic (toxo), Inflammatory (sarcoid v. whipple’s v. MS v. lupus v. PML v. Behcet’s) and Neoplastic (metastases vs. primary CNS lymphoma vs. GBM vs astrocytoma).
She had a biopsy that demonstrated primary CNS lymphoma.
Many thanks to Dr. Steve Messe for walking us through some amazing advances in stroke care- namely intra-arterial thrombectomy.
- The NIH stroke scale (<5 mild, 5-15 moderate, >15 severe) is used to assess stroke severity, and has great inter-rater reliability. It’s less sensitive for brainstem and cerebellar infarcts and those in the primary hand motor cortex (since it only assesses proximal arm strength). It’s a great predictor of short and long-term outcome.
- Mechanical intra-arterial (IA) thrombectomy has been shown in multiple trials (MR CLEAN, ESCAPE, REVASCAT) to be safe and effective, with NNTs ranging from 3-7 (!) to prevent bad neurologic outcomes
- According to guidelines, IA thrombectomy technically should be used within 6h of proximal large artery occlusion in patients with an NIHSS >6. That being said…
- …unpublished data from the DAWN study suggests that IA thrombectomy up to 24 hours after occlusion had significantly better neurological outcomes- a 73% relative risk reduction in disability in those that received thrombectomy!
- A brief note on tPA: the old teaching used to be that older patients (>80) didn’t benefit from tPA, but recent analyses suggest that older patients may actually benefit even more than younger patients. Also remember that tPA can now be used up to 4.5 hours after symptom onset (or last known normal)
- Remember that as with anything, tPA use is a risk-benefit decision; even if someone has a low NIHSS, they may still benefit from tPA if they would otherwise be disabled (ex: distal arm/hand immobility in a laborer, artist, etc)
Lastly- the paper of the day. It suggests that combining Vitamin C and thiamine with hydrocortisone in septic shock may come with a mortality benefit, but this is clearly not a randomized trial and thus more experience is probably needed. See this excellent blog post on PulmCrit for a more detailed analysis.
- Marik, P. et al. 2017. Hydrocortisone, Vitamin C, and Thiamine for the Treatment of Severe Sepsis and Septic Shock A Retrospective Before-After Study. Chest. PMID 27940189
Today we covered the often thought of (but less frequently diagnosed) bacterial meningitis and a case diagnosed and treated by our own Dr. Ferrante!
We discussed pattern recognition (“thinking fast”) and the benefits in this case. We reviewed the data on the signs and symptoms at presentation for meningitis including that having fever, neck stiffness and AMS is only 46% specific; however >95% of patients who were eventually diagnosed with bacterial meningitis had 2+ of these clinical findings (1).
We chatted about who needs a HCT prior to LP (2):
- Immunocompromized patients
- History of CNS disease (masses, stroke, focal infection)
- New onset seizure (within the last week)
- Abnormal level of consciousness (inability to answer 2 consecutive questions or follow 2 commands)
- Focal neuro defect
We also reviewed the data for dexamethasone (10mg Q6H x 4 days) started prior to antibiotics in adults. The 2002 NEJM article (3) demonstrated decreased unfavorable outcomes in the dexamethasone group as compared to the placebo (15% vs. 25% with RR 0.59). This was especially pronounced in those with S. pneumo meningitis (26% unfavorable outcome vs. 52% in placebo group). While the data for steroids improving outcomes with Neissieria is lacking, until you have the bug back, it’s worth the steroids!
Finally, we reviewed the CDC guidelines for pneumococcal vaccines and the data that demonstrated that PCV vaccination DECREASES S. Pneumo meningitis (54% reduction in incidence in those >65 during) (4).
- Attia J et al. Does This Adult Patient have Acute Meningitis? JAMA 1999;281(2): 175-181.
- Tunkel AR et al. Practice Guidelines for the management of bacterial meningitis. CID 2004;39:1267-84.
- De Gans J et al. Dexamethasone in Adults with Bacterial Meningitis. NEJM 2002;347:1549-1556.
- Hsu, HE et al. Effect of pneumococcal conjugate vaccine on pneumococcal meningitis. NEJM 2009;360:244-56.