Ankylosing spondylitis can affect the pulmonary system and cause respiratory complications like chest wall restriction, apical fibrobullous disease with or without secondary pulmonary superinfection, spontaneous pneumothorax, and obstructive sleep apnea. 

 A restrictive ventilatory impairment can develop in patients with ankylosing spondylitis because of either fusion of the costovertebral joints and ankylosis of the thoracic spine or anterior chest wall involvement.

So, apparently we don't do ADR at the level of C4-C5 because of their wide range of motion.

Also, here's this weird thing:

Cyanocobalamin cannot cross the blood-brain barrier, while mythelcobalamin can. This is why you should use the latter (not the former) for neuropathy caused by B12-deficiency.

This is called "cage and plate" implant. It's the conventional and classic technique.

There's a different "cage" technique that's called: zero-profile ACDF (Anterior Cervical Discectomy & Fusion)

هذا الفرق بين الـ cage & plate
وبين الـ zero-profile

A: Zero-profile ACDF
B: Cage & plate ACDF

Blood supply of the spinal cord

"ثلث بثنين، ثلثين بواحد"

ثلثين الـ spinal cord يغذيهن شريان واحد هو الـ anterior spinal
ثلث الـ spinal cord تغذيه شرايين ثنين هنّ الـ posterior spinal

الثلثين هاي هنّ الـ anterior المسؤولات عن الـ motor function وبما أنّ شريان واحد هو اللي يوصل الدم لهذا الجزء من الحبل الشوكي، معناها أنّه معرّض للـ ischemia أكثر من الثلث الـ posterior

An irony in the design of the human body

Almost all patients with LEMS are diagnosed with cancer within 4 years of making the diagnosis of LEMS. The most common type of cancer is SCLC (Small-Cell Lung Cancer).

Myasthenia gravis has a bimodal age-related onset, with onset in the second or third decades more common in women and onset in the sixth or seventh decades more common in men.

Tinea manuum