Richard Desruisseau, MD

A 57-year-old female presents to the emergency department with dysphagia and reports her throat is “closing up.” Recently, within the last three to four days, the dysphagia has progressed to the point of being unable to eat solid foods. On physical exam, there are no palpable masses appreciated along the neck, and the thyroid descends along the midline on swallowing and is noted to be slightly enlarged.

Contrast enhanced axial images of the neck soft tissues (Figures A, B) denote an unusual medial course of the Right Internal Carotid Artery. Figure B denotes the Right ICA just deep to the pharyngeal mucosa within the posterior oropharynx.

Midline Variation in the Course Right Internal Carotid Artery

Variations of the Internal Carotid Artery have been examined in several studies over the last 50 years. Of primary interest to the ENT and vascular specialties, the course of the ICA can have dramatic and potentially lethal consequences during otherwise low-risk procedures such as tonsillectomy or adenoidectomy.

In review of several large case series in which over 4,000 carotid angiograms were examined, variations from the typical straight course were seen in 4 percent to 66 percent of adults and 16 percent to 43 percent of children, with the majority of these abnormalities occurring bilaterally.

 In a recent study which looks at the prevalence of these variations among adults, the most common variation found is a lateral curvature of the ICA (13 percent), followed closely by medial curvature (10 percent).

 Kinking of the ICA is seen in 2.2 percent, with half of those variations in close proximity to the pharyngeal wall. Coil or loop formations of the ICA are seen in 1.7 percent of cases, with half of the formations in close proximity to the pharyngeal wall as well.

While curvature of the ICA has been attributed to part of the normal aging process and does not seem directly related to either a pathologic or congenital cause, kinking of the ICA has been associated with atherosclerotic change and or fibromuscular dysplasia. Over time, the vessel becomes tortuous as sequential plaque formation, vessel stenosis, and distal dilation distort what may have been a gentle curve or even a straight course into a sharply angled switchback. Given these associations, patients with kinking of the ICA are at an increased risk for cerebrovascular injury.

As kinking of the ICA may be seen as the dangerous variant for the elderly, the loop formation considered to be a congenital defect may be thought of as the variant of interest in the young. The loop formation is thought to be derived from a congenital lack of regression of one or more of the branchial arch vessels, predominantly the 3rd arch. These vessels do not appear to increase the risk of atherosclerotic plaque formation, and are usually asymptomatic. The formation has been called the “dangerous loop,” however, due to the high probability that formation will be in close association with the pharyngeal wall.

These dangerous and rare variants of the ICA may be encountered as a symptomatic mass, or as part of an unrelated surgical procedure, such as a biopsy or tonsillectomy. ENT and vascular surgeons should be reminded of the importance of evaluating for this potentially lethal variant. Episodes of dysphagia may be the only symptom in a patient with a dangerous variant of the vessel. Given the risk of serious complication in both young and old, investigation with duplex ultrasound or CT of the neck should be performed in order to assess the course of the ICA prior to any surgical procedure involving the pharyngeal space. In the event that a patient has a pulsatile mass along the neck that is not observed to be related to the ICA by CT angiography, 

Treatment of patients with symptomatic tortuous internal carotid arteries include: endarterectomy, covered stenting, or vessel grafting, depending on the severity of the atherosclerotic change.

 Given previously stated increased risk for CVA, clinicians should be vigilant for neurologic sequelae following vascular procedures in this patient population. TIA has been shown to be the most common neurologic complication post-procedure; however, permanent neurologic deficit may occur in rare cases.

Submitted by David Hunte, MS-IV, (School of Medicine) and Richard Desruisseau, MD, Department of Radiology at Meharry Medical College, Nashville, Tenn.

1. Desai B & Toole J. Kinks Coils and Carotids: A Review. Stroke. 1975; 6:649-653
2. Paulsen P. Curving and looping of the internal carotid artery in relation to the pharynx: frequency, embryology and clinical implications. Journal of Anatomy Royal Society of Medicine; 2000; 197: 373-381
3. Windfuhr J. A devastating outcome after adenoidectomy and tonsillectomy: Ideas for improved prevention and management. Otolaryngology Head and Neck Surgery. 2009; 140: 191-1973. 
4. Radonic V. Surgical treatment of kinked internal carotid artery. Journal of Cardiovascular Surgery (Torino).1998 Oct; 39(5):557-63.

Articles

A 57-year-old female presents to the emergency department with dysphagia and reports her throat is “closing up.” On physical exam, there are no palpable masses appreciated along the neck, and the thyroid descends along the midline on swallowing and is noted to be slightly enlarged.

Aberrant ICA


32 year old African American female presented with a complaint of headaches located in the temporal region.  Pain described as sharp, rated 10/10, with sudden onset, and no exacerbating or relieving factors.  She also complained of loss of peripheral vision in her right eye.

The onset of her headache began 8 days postpartum. She admitted to vertigo but no weakness, fever, neck stiffness or ataxia.  She denied any change in intensity of headache with change in position.  The remainder of her history was unremarkable.


Axial T1 weighted image of the brain demonstrated a ring-like region of signal hyperintensity within the left posterior parietal lobe (Figure 1). 

Axial T2 weighted image demonstrated a corresponding large area of heterogeneously increased signal within the left posterior parietal lobe (Figure 2).

Magnetic Resonance Venogram  (MRV) demonstrated absence of normal signal within the left transverse and sigmoid dural venous sinuses (Figure 3). 

Axial T1 (Figure 4A) and axial T2 (Figure 4B) 1yr follow up images demonstrate much smaller areas of probable encephalomalacia and ring-like chronic hemorrhage (hemosiderin deposition) within the left posterior parietal lobe.  Hematology panels were unremarkable for infection, genetic deficiencies, and/or acquired thrombophilias. 


Dural Venous Thrombosis with hemorrhagic infarct of left parietal lobe


Dural venous sinus thrombosis (DVT) is rare. In adults the incidence is 3 to 4 cases per million (1) and occurs more frequently in women than men; 75% of cases are seen in women (2,4). The most frequent predisposing factors for (DVT) are genetic and acquired prothrombotic states, such as pregnancy (especially the third trimester) and the puerperinum period. Infection and the use of oral contraceptives are other predisposing factors (5). 

During pregnancy, there are changes to fibrinogen, and clotting factors levels that constitute a relatively hypercoagulable state (3).  An occluded cerebral vein causes a backup of pressure and bland ischemic infarctions with or without subsequent hemorrhage (2). The resultant increased pressure from the thrombosed sinus (especially Superior and Lateral Sagittal Sinuses) blocks circulation and absorption of cerebral spinal fluid (CSF) causing intracranial hypertension (5).  Venous infarcts are more commonly hemorrhagic, tend to have a non-arterial distribution, and their occlusion is usually located in a major dural sinus (7). In fact, the superior sagittal and transverse sinus thrombi are the most commonly occurring dural thrombi.

The signs and symptoms of dural sinus thrombosis are occasionally nonspecific and highly variable, making the clinical diagnosis difficult.  Headache is the most common presenting symptom, and occasionally the only indicator.  The diagnosis for postpartum headache can be categorized into those of primary cause or secondary cause.  Primary cause headaches include migraine, cluster and tension headaches.  Secondary cause headaches may include: venous sinus thrombosis, ischemic and/or hemorrhagic stroke (hypertensive, subarachnoid or vascular malformations), arterial dissection, and reversible cerebral vasoconstrictive syndromes (8).  Because of the nonspecific manner in which dural sinus thrombosis presents, it is important that MRI, MRA, and MRV neuroimaging be done on postpartum patients presenting with headache (6).


Elevated ICP can lead to secondary cerebral damage and special measures should be taken to normalize the pressure.  Acetozolamide is the diuretic of choice to reduce intracranial pressure. External ventricular drainage and CSF shunts can be used but have associated increased risk of complications (5).  Patients with postpartum DVT, without any contraindications, should be treated with intravenous or subcutaneous body-weight adjusted low molecular weight heparin.  Proper anticoagulation therapy is the main focus for treating DVT in the acute setting. It should include oral vitamin K antagonists administered for 3 months or continued for a lifetime depending on the underlying cause (8).

Submitted by Dean Thompson, MS-III (School of Medicine) and Richard Desruisseau, M.D., Department of Radiology at Meharry Medical College, Nashville, TN. Special thanks to Pradumna Singh, M.D., Department of Neurology at Meharry Medical College.

1. Agnelli G, Verso M: Epidemiology of cerebral vein and sinus thrombosis. Front Neurol Neurosci 2008 2F: 16-22
2. Neurologic Diseases in Women 2nd ed, Peter W. Kaplan 2006
3. Ciliberto C, Marx GF: Physiological changes associated with pregnancy. Update in Anaesthesia 1998; 9: 1-3
4. Stam J: Thrombosis of the cereberal veins and sinues. N Engl J Med 2005; 352:1791-1798
5. Phillippidis A et all: Cerebral venous sinous thrombosis: review of the demographics, pathophysiology, current diagnosis, and treatment. Neurosurg Focus 2009, 27
6. Bousser MG, Ferro JM: Cerebral venous thrombosis: an update.  Lancet Neurol 2007; 6:162-170
7. Diagnostic Imaging: Brain. Osborn et al Amirsys 1st ed 2004
8. Klein AM, Loder E. Postpartum headache. International Journal of Obstetric Anesthesia 2010; 19: 422-430
 

A 32 year old African American female presents with temporal region headaches, including sudden onset of extreme pain with no exacerbating or relieving factors, as well as peripheral vision loss in the right eye. MRI, MRA, and MRV added diagnosis.

Dural Venous Thrombosis

A 29 year old female presented to the Emergency Department with complaint of chest pain for the past 5 days. This pain initiated on the left side and is now bilateral. It is exacerbated with movement and breathing. There is no fever, cough, or chills. No treatment was received prior to arrival.

Tuberous Sclerosis Complex is a rare, inherited neurocutaneous disorder that is known to cause benign hamartomas in a range of organ systems, including the brain, eyes, skin, lung, liver, kidneys, and heart. The expression of this disease varies substantially. GENETICS: This disease is an autosomal dominant disorder however only one-third of cases are familial. The other two-third of cases are caused by either mosaicism – where some cells have the mutation and others do not or spontaneous mutations. A mutation in TSC1 and TSC2 genes which are located on chromosome 9 and chromosome 16, respectively have been identified to be the major cause of this disease. The proteins that are coded by these 2 genes are known to interact and form a complex that negatively regulate the cell cycle.1

CLINICAL FEATURES: Presentation of seizures, mental retardation, and facial angiofibromas is called the classic triad of TSC also known as Vogt’s triad. Less than 50 percent of patients, however, presents with this triad. In the past, this made it difficult for physicians to diagnose the majority of these patients. Therefore in 1998, a range of presentation of Tuberous Sclerosis Complex were grouped into major and minor diagnostic criterias. Presentation of two major criterias or one major and two minor criterias, encompasses a diagnosis for TSC.2

Major criterias are Facial angiofibromas, shagreen patch, hypomelanotic macules, periungual fibromas, Lymphangioleiomyomatosis, subependymal nodules, renal angiomyolipoma, cortical tubers, subependymal giant cell astrocytoma, subependymal nodules, multiple retinal nodular hamartomas, and cardiac rhabdomyoma. Minor criterias are confetti skin lesions, multiple renal cyst, gingival fibromas, pits in the dental enamel, cerebral white matter radial migration lines, nonrenal hamartomas, bone cyst, and retinal achromic patch. Exception is that isolated finding of Lymphangioleiomyomatosis (LAM) and renal angiomyolipoma in a patient, does not place them at a higher risk of having an affected child and therefore these patients are not considered to have TSC.

Management of TSC is dependent on the presentation of the patient. Of most concern would be the control of major causes of death in this patient population. Subependymal giant cell tumors and status epilepticus are the most common causes of death.3 Surgical resection of brain tumors is indicated when there is an hydrocephalus or increased intracranial pressure, interval increase in tumor size, or new focal neurological deficit that is attributable to the tumor. Additive and less frequent causes of death are renal complications such as renal cell carcinoma, hemorrhage into angiomyolipoma, and renal failure.

Submitted by Ellis Enabosi, MS-III (School of Medicine) and Richard Desruisseau, M.D., Department of Radiology (Chief, Musculoskeletal Section) at Meharry Medical College, Nashville, TN.


 
References:
1. Tee AR, Fingar DC, Manning BD, et al. Tuberous sclerosis complex-1 and -2 gene products function together to inhibit mammalian target of rapamycin (mTOR)-mediated downstream signaling. Proc Natl Acad Sci U S A 2002; 99:13571.
2. Roach ES, Gomez MR, Northrup H. Tuberous sclerosis complex consensus conference: revised clinical diagnostic criteria. J Child Neurol 1998; 13:624. 
3. Shepherd CW, Gomez MR, Lie JT, Crowson CS. Causes of death in patients with tuberous sclerosis. Mayo Clin Proc 1991; 66:792.
 

29 year old female presented to the Emergency Department with complaint of chest pain for the past 5 days. This pain initiated on the left side and is now bilateral. It is exacerbated with movement and breathing. There is no fever, cough, or chills. No treatment was received prior to arrival.

Tuberous Sclerosis Complex

A 51-year-old woman presented to the clinic complaining of left heel pain. On physical exam there was tenderness and soft tissue swelling of the posterior aspect of the left heel. Conventional radiographs of the left ankle were obtained in anteroposterior, lateral, and oblique views. They were essentially unremarkable, although the lateral view showed equivocal prominence of the posterior superior calcaneal tuberosity, along with subtle findings of increased density in the pre-Achilles fat (arrows, Figure 1). MR imaging was subsequently performed.

Sagittal T1-weighted image (Figure 2) demonstrates focal decreased T1 signal within the pre-Achilles fat, as well as a prominent posterior superior calcaneal tuberosity (arrow). Sagittal proton density image (Figure 3) shows increased signal intensity in the pre-Achilles fat/retrocalcaneal bursa (arrow). Sagittal T2-weighted image (Figure 4) reveals mildly increased signal intensity within the distal Achilles tendon without evidence of a full-thickness tear. Axial T2-weighted image (Figure 5) better demonstrates increased signal intensity within the Achilles tendon (arrow) with associated retrocalcaneal inflammatory disease.

Haglund’s deformity, commonly referred to as “pump bump,” is an enlargement of the posterior superior calcaneal tuberosity. Friction between the bony enlargement and Achilles tendon causes soft tissue inflammation, resulting in retrocalcaneal bursitis. This constellation of Achilles tendinosis, the bony enlargement, and retrocalcaneal bursitis constitute Haglund’s complex.

 This condition is most commonly seen in young women who wear pump-style shoes. These shoes irritate the soft tissue by placing increased pressure on the bony enlargement. Other individuals who are prone to this condition include those with naturally high arches or a tight Achilles tendon.

Symptoms include pain at the Achilles tendon insertion site, erythema and swelling of the heel, and pain that is aggravated by dorsiflexion.

Initial treatment consists of conservative methods such as oral anti-inflammatory medications, heel lifts, ice, shoe modification, and calf-stretching exercises. Steroid injections are usually avoided in cases of Achilles tendinitis to avoid subsequent tendon rupture. If these methods are unsuccessful, surgery is considered.

MRI is the modality of choice in differentiating common causes of heel pain such as, but not limited to, plantar fasciitis, fracture, tarsal tunnel syndrome, bursal abnormalities, or tendon rupture.

Heel pain is a common complaint and many times can be managed conservatively. However, in cases where etiology is questionable and medical management is unsuccessful, MR imaging is useful in determining not only the diagnosis, but also the extent and severity of disease.




Ms. Crawford is a medical student and Dr. Desruisseau is a physician in the Radiology department at Meharry Medical College in Nashville, TN.

1. Stephens MM. Haglund’s deformity and retrocalcaneal bursitis. Orthop Clin North Am 1994;25(1):41-46.
2. NarvÃ¡ez JA, NarvÃ¡ez J, Ortega R, et al. Painful heel: MR imaging findings. Radiographics 2000;20(2):333-352.

A 51-year-old woman presented to the clinic complaining of left heel pain.Tenderness and soft tissue swelling were observed. MRI reveals Haglund's deformity. 

Richard Desruisseau, MD

Articles

Aberrant ICA

Dural Venous Thrombosis

Tuberous Sclerosis Complex

MRI reveals cause of heel pain