Anterior Arch of Atlas Fissure-CT

This 8 yr old child had minor injury and then was unable to rotate his neck. Anterior arch of the atlas appears congenitally split and shows 5mm gap in the anterior arch possibly indicating fissure in the anterior arch. Although, altantodental distance is maitained, there is some altered articulation in the atltanto-axial articulation.  Torticollis has been reported after minor trauma in patients with split atlas.  Reference- Torticollis of a Specific C1 Dislocation With Split Atlas. Spine: 15 June 2010 - Volume 35 - Issue 14 - pp E672-E675.

Hot Cross Bun Appearance-MRI

The hot cross bun sign is seen on transverse T2-weighted magnetic resonance images of the brain as a cruciform hyperintensity in the pons This appearance is seen in patients with MSA-c. The sign is due to a selective loss of myelinated transverse pontocerebellar fibers and neurons in the pontine raphe with preservation of the pontine tegmentum and corticospinal tracts.  Note in our case of 47 year old female, cruciform hyperintensity in pons, cerebellar atrophy and high signal in the middle cerebellar peduncles, possibly MSA-c.

Chikungunya fever & Carpal Tunnel Syndrome-MRI

"Chikungunya fever is a re-emerging viral disease, especially in South India, characterised by abrupt onset of fever with severe arthralgia followed by generalized fatigue, fever, chills, nausea, vomiting, lower back pain and rash lasting for 1-7 days.  Neurologically, encephalopathy is the most common sequela, with alterred sensorium and ataxia.  On MRI, multiple high-intensity areas are seen. There are no spinal cord changes. Other common neurologic manifestations are myelopathy, polyradiculopathy, neuropathy (early > late), and carpal tunnel syndrome (2/2 excess synovial fluid and swelling) as seen in our lady patient who had chikungunya followed by carpal tunnel syndrome. "

Early Cavernous Sinus Thrombosis-Gd MRI

The cavernous sinuses receive venous blood from the facial veins (via the superior and inferior ophthalmic veins) as well as the sphenoid and middle cerebral veins. They, in turn, empty into the inferior petrosal sinuses, then into the internal jugular veins and the sigmoid sinuses via the superior petrosal sinuses. This complex web of veins contains no valves; blood can flow in any direction depending on the prevailing pressure gradients. This is diabetic female with clinical history of multiple cranial nerve palsies. Case submitted by Dr MGK Murthy.

Teaching points

• Multiple cranial nerve palsies in diabetic lady should always suggest infection base of the skull and venous thrombosis unless other wise proved
• Superior opthalmic vein is sensitive indicator of things hapening in cavernous sinus 
• Base of the  skull in this case shows diffuse enhancing oedema -producing literally sheet of gadolinium possibly encasing all the foramina at base including foramen ovale
•  Widened cavernous sinus with some asymetry is suggestive of stasis and thrombus along with asymmetry of flow void of ICA within
• No proptosis is no guarantee against venous thrombosis 
• Sphenoid sinus is is notorious for producing base of the skull and meningeal inflammation
• All muslces and soft tissues including temporalis are inflammed
  
  

Residents are NOT students-NEJM

An interesting article in NEJM- Residents: Workers or Students in the Eyes of the Law? NEJM | January 12, 2011 | Topics: Health Law. sparks off a debate on liability of resident doctor if he errs, does the court take him as student or is he liable in the same way as senior doctors. 

According to recent court verdict cited in the article --" On January 11, 2011, the Supreme Court ruled in an 8-to-0 decision (Justice Elena Kagan was recused) that the Treasury regulation making residents categorically ineligible for the student exemption was a “perfectly sensible” way of distinguishing education from service for the purposes of the tax code."

Lateral medullary syndrome (Wallenberg syndrome)

Findings

Axial FLAIR (Figure 1 and Figure 2) and T2-weighted (Figure 3 and Figure 4) images demonstrate mild signal hyperintensity in region of the left lateral and posterior medulla PICA territory.
Axial DWI (Figure 5 and Figure 6) and matching ADC maps (Figure 7 and Figure 8) demonstrate true restricted diffusion in the left lateral and posterior medulla PICA suggestive of cytotoxic edema fort an acute infarction.
3D TOF posterior circulation MIP projection (Figure 9) demonstrates absence of a normal left PICA. It's possibile to see the right PICA for comparison, arising from the distal right intracranial vertebral artery. There is also a mild narrowing of the basilar artery. It's possibile also to appreciate bith the superior cerebellar arteries.


Diagnosis: Lateral medullary syndrome (Wallenberg syndrome)


Adolf Wallenberg (November 10, 1862-1949) was a German internist and neurologist who first described the clinical manifestations (1895) and the autopsy findings (1901) in occlusions of the arteria cerebelli posterior inferior (Wallenberg syndrome).

Lateral medullary syndrome is characterized by sensory deficits affecting the trunk and extremities on the opposite side of the infarct and sensory, and motor deficits affecting the face and cranial nerves on the same side with the infarct. Other clinical symptoms and findings include ataxia, facial pain, vertigo, nystagmus, diplopia, Horner syndrome, and dysphagia. The cause of this syndrome is secondary to occlusion of the PICA near its origin. Similar symptoms may be produced by vertebral artery occlusion near the origin of the PICA.

Afflicted persons can have dysphagia resulting from involvement of the nucleus ambiguus and slurred speech (dysphonia and dysarthria). Damage to the spinal trigeminal nucleus causes absence of pain on the ipsilateral side of the face as well as an absent corneal reflex. The spinothalamic tract can be damaged, resulting in loss of pain and temperature sensation to the opposite side of the body. Damage to the cerebellum can cause ataxia. Damage to the hypothalamospinal fibers disrupts sympathetic nervous system relay and gives symptoms analogous to Horner syndrome (ptosis, anhidrosis, and miosis).

In older patients, the most common cause of posterior circulation ischemia is thromboembolic disease resulting from accelerated atheromatous disease or embolic disease from a cardiac source. In young patients with posterior fossa ischemia, in addition to embolic disease, the diagnosis of arterial dissection should also be considered.
Wallenberg syndrome synonyms: dorsolateral medullary syndrome, lateral bulbar syndrome, lateral medullary infarction syndrome, and PICA syndrome.

Transient bone marrow oedema of the hip-MRI

Transient bone marrow oedema of the hip also referred as transient osteoporosis of the hip is self-limited conditions that improves spontaneously over several months.  TOH was first described in 1959 in two women in their 3rd trimesters of pregnancy but now is more commonly seen in middle-aged men. This is 34 yr old female, immediate post partum, note the bulky uterus and marrow edema involving the right femoral head and neck, along with increased synovial fluid.