new_n_lost
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A 16 year old girl presented with a three week history of headache and horizontal diplopia on far right lateral gaze. On two separate occasions she noted dimmed vision whilst bending forwards. Over the last year she had gained 12 kilograms in weight. On examination, her weight was 95 kg, and height 162cms. Neurological examination revealed bilateral papilloedema and a partial right sixth cranial nerve palsy.
What is the most likely diagnosis?
1) Benign intracranial hypertension
2) Multiple sclerosis
3) Pituitary tumour
4) Superior sagittal vein thrombosis
5) Thyroid eye disease
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| mytime
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1
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| new_n_lost
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 Nobody Answers n So many Views Cmon Guys SHOW UR GUTS
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| salmonella
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may be 3
as pitutary tumor compress 6th nerve when enlarged laterally
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| mms
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3 ?
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| silver
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3 
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| silver
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just for nnl's sake: i came up with this answer after a detailed discussion with nnl
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it's 1
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| new_n_lost
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This patient is markedly obese with a BMI of 36 and the history suggestive of BIH. Vision may be affected with enlargement of the blind spot and the visual obscuration with movements that provoke a rise in ICP (eg bending) is typical of BIH.
Dysthyroid eye disease would not present like this and is more commonly associated with Hyperthyroidism.
The papilloedema would argue against MS.
A bitemporal hemianopia or a visual field defect would be expected with a pituitary tumour.
Venous sinus thrombosis is a possibility but would be expected to produce deteriorating symptoms.
Edited by new_n_lost on 04/08/07 - 06:36 PM
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| new_n_lost
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Benign Intracranial Hypertension
History:
- Patients usually present with symptoms related to increased intracranial pressure. These symptoms include headache, transient visual obscurations, and diplopia due to unilateral or bilateral sixth nerve palsy. Rarely, patients presenting with increased intracranial pressure with related optic nerve edema may be asymptomatic.
- Nonspecific symptoms may include dizziness, nausea, vomiting, and tinnitus.
- Headaches are recorded in 99% of patients presenting to neurologists and slightly less in patients presenting to ophthalmologists.
- The pain is generally described as being diffuse, which worsens in the morning and is exacerbated by the Valsalva maneuver.
- Transient visual obscurations: This visual symptom occurs in most patients. The disturbance usually lasts 1-5 seconds and is described as a graying out of vision. Orthostatic changes, such as standing up or bending over, induce this symptom.
- Diplopia: Patients who present with double vision most frequently complain of horizontal displacement of the images. Vertical diplopia is rare, but it has been reported.
Physical: - The most significant finding in patients with this disease is bilateral disc edema secondary to the increased intracranial pressure.
- This papilledema varies from patient to patient and is indistinguishable from optic nerve swelling caused by intracranial space-occupying lesions. In more pronounced cases of disc swelling, macular involvement with subsequent edema and diminished central vision may be present. High-grade and atrophic papilledema in addition to subretinal hemorrhages are poor visual prognostic signs.
- In some instances, the disc swelling is asymmetric, or, rarely, the appearance of the optic nerve may be relatively normal.
- If left untreated, chronic disc swelling eventually leads to clinically significant visual loss. Although all patients present with enlarged blind spots during their initial perimetry, uncontrolled papilledema results in progressive peripheral visual field constriction or nerve fiber bundle defects (eg, nasal depression, nasal steps, arcuate scotomas).
- The central visual field is affected in end-stage chronic papilledema.
- Sudden loss of central vision may result from an associated anterior ischemic optic neuropathy, a vascular occlusion, or an associated subretinal neovascular membrane.
- The diplopia noted in patients with idiopathic intracranial hypertension is invariably due to unilateral or bilateral sixth nerve palsy. These cranial nerve palsies diminish with the lowering of the intracranial pressure.
- Occasionally, patients with diplopia present with oculomotor or trochlear nerve palsy.
- In rare instances, vertical diplopia is due to a skew deviation.
Causes: - Most cases of pseudotumor cerebri occur in young women who are obese and, less frequently, in men who are otherwise healthy.
- If this disorder presents in an individual who is not overweight, ruling out associated risk factors is necessary. These risk factors include systemic diseases (including Lyme disease), disruption of cerebral venous flow, certain endocrine or metabolic disorders, and exposure to or withdrawal from certain exogenous substances.
- Exogenous substances
- The list of exogenous substances associated with idiopathic intracranial hypertension is extensive. Although an association exists between these substances and this disorder, the exact causal relationship is somewhat lacking in the literature.
- Exogenous substances associated with idiopathic intracranial hypertension include amiodarone, antibiotics (eg, nalidixic acid, penicillin, tetracycline), carbidopa, levodopa, chlordecone, corticosteroids (eg, topical, systemic), cyclosporine, danazol, growth hormone, indomethacin, ketoprofen, lead, leuprolide acetate, levonorgestrel implants, lithium, oral contraceptives, oxytocin, perhexiline, phenytoin, and vitamin A (>100,000 U/d)/retinoic acid.
- In some instances, although a patient may present with idiopathic intracranial hypertension following exposure to a certain medication, the disorder can continue despite the cessation of the presumed offending agent.
- Ironically, withdrawal from corticosteroids may result in idiopathic intracranial hypertension.
- Systemic diseases
- A myriad of illnesses are associated with idiopathic intracranial hypertension. Some of these disorders result in an increased viscosity of the cerebrospinal fluid. However, in most of the listed entities, the causal link with raised intracranial pressure is not clear.
- The following diseases have been associated with idiopathic intracranial hypertension: anemia, chronic respiratory insufficiency, familial Mediterranean fever, hypertension, multiple sclerosis, polyangiitis overlap syndrome, psittacosis, renal disease, Reye syndrome, sarcoidosis, systemic lupus erythematosus, and thrombocytopenic purpura.
- Disorders of cerebral venous drainage
- Cerebral venous compression by extravascular tumors or secondary thrombosis results in impaired absorption of the cerebrospinal fluid and, thus, pseudotumor cerebri. Restriction of venous drainage from the head may be impaired with radical neck dissection, even if completed only on the right side (predominant drainage from the head is via the right jugular vein). Spontaneous recanalization usually occurs, but, if delayed, chronic papilledema may result.
- The diagnosis of cerebral sinus thrombosis may be missed with the exclusive use of computed tomography (CT). Therefore, either in patients who present atypically or in management dilemmas, ruling out cerebral venous thrombosis with the use of magnetic resonance imaging (MRI)/venography is worthwhile.
- Endocrine disturbances: Pregnancy is occasionally associated with idiopathic intracranial hypertension. This disorder can present at any stage of pregnancy. Given the limitations of neuroimaging studies and of medically treating patients who are pregnant, both the diagnosis and the management of these patients are determined on a case-by-case basis. Any neuroimaging studies or therapeutics should be performed in conjunction with the patient's obstetrician
Edited by new_n_lost on 04/08/07 - 06:35 PM
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| new_n_lost
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The disease commonly occurs in women who are overweight. The role of obesity in this disorder is unclear. Obesity has been proposed to increase intra-abdominal pressure, which, in turn, raises cardiac filling pressures. This rise in pressure leads to impeded venous return from the brain (due to the valveless venous system that exists from the brain to the heart) with a subsequent elevation in intracranial venous pressure. If not treated appropriately, chronic interruption of the axoplasmic flow of the optic nerves with ensuing papilledema due to this pressure may lead to irreversible optic neuropathy.
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| keepgoing
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Thanks nnl appreciate it!
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| usmle4me
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Very nice explaination.thanks for your time and effort.
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| rock
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good question and better explanation
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| salmonella
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very nice explaination
but i have qs if pitutiary is enlarged laterally in cavernous sinus it will compress sixth nerve but not bitemp hemianopsia.then how can u rule out that
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| salmonella
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and in pitutiar adenoma in cavernous sinus also presents with symptoms related to increased intracranial pressure. These symptoms include headache, transient visual obscurations, and diplopia due to unilateral or bilateral sixth nerve palsy
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| new_n_lost
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salmonella wrote:
and in pitutiar adenoma in cavernous sinus also presents with symptoms related to increased intracranial pressure. These symptoms include headache, transient visual obscurations, and diplopia due to unilateral or bilateral sixth nerve palsy
A Pituitary Adenoma is a Slow Growing Tumor n the Effects wont be alternating infact they will be consistent n persisitent AS the Explanation also suggests that the A Bitemporal Heminopia wud like lead u toeard a Pituitary Adenoma
- Ocular paresis (78%) results from compression of the cavernous sinus, which make cranial nerves III, IV, VI vulnerable to compression.
- If consciousness is maintained, diplopia may be present.
- Of the cranial nerves, the oculomotor nerve is involved most commonly, resulting in a unilateral dilated pupil, ptosis, and a globe that is deviated inferiorly and laterally.
- Less commonly, cranial nerve IV is involved.
- A fourth cranial nerve palsy typically manifests as vertical diplopia that worsens when the patient gazes in a direction opposite or tilts the head toward the direction of the hypertropic (affected) eye. It also is worsened by downgaze.
- The sixth cranial nerve is least commonly involved, perhaps because of its sheltered position in the cavernous sinus. Its involvement produces horizontal diplopia, which results from inability to abduct the involved eye.
- By virtue of its existence in the cavernous sinus, trigeminal nerve involvement may produce facial pain or sensory loss.
Visual acuity defects (52%) and visual field defects (64%) result from upward expansion of the tumor, which compresses the optic chiasm, optic tracts, or optic nerve.
- The classic visual field defect is a bitemporal superior quadrantic defect.
- Optic tract involvement from a prefixed chiasm is less common and results in a contralateral homonymous hemianopia.
- Optic nerve compression from a postfixed chiasm is rare and may mimic optic neuritis with pain on eye movement, monocular visual acuity loss, and a central scotoma on visual field testing.
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| salmonella
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| new_n_lost
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salmonella wrote:
very nice explaination
but i have qs if pitutiary is enlarged laterally in cavernous sinus it will compress sixth nerve but not bitemp hemianopsia.then how can u rule out that
If its a Pit MAcroadenoma then the likelihood of it going on laterally will be less. it can n it does normally involve the Optic Chiasm or the Optic Tracts. True the Visual symptoms are generally related to compression of visual pathways and include bitemporal visual-field loss, which is denser from the superior to inferior than in other orientations, color desaturation, diplopia, and ophthalmoplegia. but If we try to Localize a Pt on the basis of Visual Acuity then a laterally growing tumor falls way down th elists n will present with other features.
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| new_n_lost
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salmonella wrote:
Cant understand the reason for the 2nd Smiley ??
Did u get it or not still some confusion if there is lets discuss it post it here n it will be beneficial for all of us.
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| salmonella
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good job nnl
i read the qs again and all the explaination so now i got two differentiating points that isweight gain and secondly least common invoved nerve in pitutiary is 6th .
thanks a lot again
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