Sylvian Aqueduct Syndrome Research Articles

Diagnosis and Treatment of Sylvian Aqueduct Syndrome.

Sylvian aqueduct syndrome is a rare complication after ventriculoperitoneal (V-P) shunt surgery and is not easily diagnosed. A 26-year-old male with obstructive hydrocephalus due to tectal glioma was treated with a V-P shunt surgery in another hospital. After the surgery, the patient developed an intractable disturbance of consciousness. When the V-P shunt pressure was raised or lowered, the patient's consciousness disorder still could not be improved. The patient was diagnosed with Sylvian aqueduct syndrome, a rare complication after V-P shunt operation. The paper clarifies the treatment experience with simultaneous endoscopic third ventriculostomy (ETV) and tectum gliomas biopsy, postoperative pathology suggestive of fibrillary astrocytoma; after surgery, the Sylvian aqueduct syndrome was cured and the patient recovered well. The preferred treatment for obstructive hydrocephalus caused by tumors in the Pineal region is the ETV operation. If an ETV operation and biopsy operation are performed simultaneously, more details need to be noted.

Sylvian Aqueduct Syndrome and Parkinsonism in Aqueduct Stenosis

Objective and Importance: Sylvian aqueduct syndrome (SAS) is associated with a complex clinical picture, which suggests global rostral midbrain dysfunction. Clinical Presentation: A 34-year-old woman developed SAS and Parkinsonism secondary to aqueductal stenosis and was treated by endoscopic third ventriculostomy (ETV) as an initial treatment, which led to the successful resolution of the symptoms. At admission, she exhibited only memory disturbance, slight cognitive impairment and urinary incontinence after recent childbirth. Magnetic resonance imaging (MRI) revealed aqueductal stenosis with the enlargement of the third and lateral ventricle with normal sized fourth ventricle. Several days later, the patient displayed upward gaze paralysis (Parinaud’s syndrome), Parkinsonian hands tremor, and somnolent confusional state. An MRI revealed abnormal intensity in the midbrain and upper pons as well as bulging of the posterior portion of the third ventricle. The dramatic resolution of the patient’s Parinaud’s syndrome, Parkinsonian tremor, and drowsy state after ETV was accompanied by the disappearance of the abnormal intensity in the midbrain and posterior bulging of the third ventricle. This characteristic change, which occurred simultaneously in both the clinical and MRI findings, revealed the lesion responsible for the SAS and Parkinsonism. A drastic change in the ventricular size or transtentorial pressure gradient might have also caused distortion and stretching of the midbrain. Conclusions: The simultaneous resolution of the clinical symptoms and abnormal MRI findings after ETV revealed the lesion responsible for this patient’s SAS and Parkinsonism. Early ETV allowed the reversal of the SAS and Parkinsonism and should be considered as the first-line treatment.

Sylvian aqueduct syndrome with slit ventricles in shunted hydrocephalus due to adult aqueduct stenosis

The authors report on 3 patients who developed sylvian aqueduct syndrome (SAS) in the context of shunt dysfunction and slit ventricles. All 3 patients had received shunts for adult onset hydrocephalus due to aqueduct stenosis and were stable for years before presenting with loss of upward gaze, convergence-retraction nystagmus, and slit ventricles, all due to shunt overdrainage. All 3 improved after either shunt revision or a third ventriculostomy procedure. Although it is well known that SAS can be caused by shunt blockage producing a transtentorial pressure gradient, these cases emphasize that an identical clinical pattern can occur with a reverse transtentorial pressure gradient and slit ventricles due to shunt overdrainage. The authors propose a simple management plan for patients with shunted hydrocephalus who develop SAS.

Sylvian aqueduct syndrome and global rostral midbrain dysfunction associated with shunt malfunction.

This study is a retrospective analysis of clinical data obtained in 28 patients affected by obstructive hydrocephalus who presented with signs of midbrain dysfunction during episodes of shunt malfunction. All patients presented with an upward gaze palsy, sometimes associated with other signs of oculomotor dysfunction. In seven cases the ocular signs remained isolated and resolved rapidly after shunt revision. In 21 cases the ocular signs were variably associated with other clinical manifestations such as pyramidal and extrapyramidal deficits, memory disturbances, mutism, or alterations in consciousness. Resolution of these symptoms after shunt revision was usually slow. In four cases a transient paradoxical aggravation was observed at the time of shunt revision. In 11 cases ventriculocistemostomy allowed resolution of the symptoms and withdrawal of the shunt. Simultaneous supratentorial and infratentorial intracranial pressure recordings performed in seven of the patients showed a pressure gradient between the supratentorial and infratentorial compartments, with a higher supratentorial pressure before shunt revision. Inversion of this pressure gradient was observed after shunt revision and resolution of the gradient was observed in one case after third ventriculostomy. In six recent cases, a focal midbrain hyperintensity was evidenced on T2-weighted magnetic resonance imaging sequences at the time of shunt malfunction. This rapidly resolved after the patient underwent third ventriculostomy. It is probable that in obstructive hydrocephalus, at the time of shunt malfunction, the development of a transtentorial pressure gradient could initially induce a functional impairment of the upper midbrain, inducing upward gaze palsy. The persistence of the gradient could lead to a global dysfunction of the upper midbrain. Third ventriculostomy contributes to equalization of cerebrospinal fluid pressure across the tentorium by restoring free communication between the infratentorial and supratentorial compartments, resulting in resolution of the patient's clinical symptoms.

Sylvian aqueduct syndrome and global rostral midbrain dysfunction associated with shunt malfunction

Object This study is a retrospective analysis of clinical data obtained in 28 patients affected by obstructive hydrocephalus who presented with signs of midbrain dysfunction during episodes of shunt malfunction. Methods All patients presented with an upward gaze palsy, sometimes associated with other signs of oculomotor dysfunction. In seven cases the ocular signs remained isolated and resolved rapidly after shunt revision. In 21 cases the ocular signs were variably associated with other clinical manifestations such as pyramidal and extrapyramidal deficits, memory disturbances, mutism, or alterations in consciousness. Resolution of these symptoms after shunt revision was usually slow. In four cases a transient paradoxical aggravation was observed at the time of shunt revision. In 11 cases ventriculocisternostomy allowed resolution of the symptoms and withdrawal of the shunt. Simultaneous supratentorial and infratentorial intracranial pressure recordings performed in seven of the patients showed a pressure gradient between the supratentorial and infratentorial compartments with a higher supratentorial pressure before shunt revision. Inversion of this pressure gradient was observed after shunt revision and resolution of the gradient was observed in one case after third ventriculostomy. In six recent cases, a focal midbrain hyperintensity was evidenced on T2-weighted magnetic resonance imaging sequences at the time of shunt malfunction. This rapidly resolved after the patient underwent third ventriculostomy. It is probable that in obstructive hydrocephalus at the time of shunt malfunction, the development of a transtentorial pressure gradient could initially induce a functional impairment of the upper midbrain, inducing upward gaze palsy. The persistence of the gradient could lead to a global dysfunction of the upper midbrain. Conclusions Third ventriculostomy contributes to equalization of cerebrospinal fluid pressure across the tentorium by restoring free communication between the infratentorial and supratentorial compartments, resulting in resolution of the patient's clinical symptoms.

視床梗塞により生じたふくそう眼振の２症例

Convergence nystagmus, which is a main finding in Sylvian aqueduct syndrome is not common. We examined two patients of convergence nystagmus associated with infarction of the thalamus. The patients, aged 21 and 64-years, visited our clinic because of sudden dizziness. There was no cochlear sign in either case. Neurotological examinations, including electronystagmography (ENG), were carried out. Both patients had up-beat nystagmus, convergence nystagmus and abnormal vertical eye movements; however, no upward gaze palsy was observed. One patient showed a normal response to caloric testing, but the other showed rt-canal paresis (41%). On computerized tomography (CT scan), no lesion could be identified in the midbrain or thalamus of either patient. However, in one patient, T2-weighted MRI revealed a high signal region and Ti-weighted MRI demonstrated a low signal region in the lt-medial part of the thalamus. In the second patient, T2-weighted MRI revealed multiple bilateral lacunar high signal lesions in the thalamus, the putamen and in the region of the deep white matter. The etiology of abnormal vertical eye movements and convergence nystagmus is discussed with emphasis on the neurotological examinations and MRI.Convergence nystagmus may be associated with lesions of the posterior commisure and nucleus in the medial part of the thalamus, and abnormal vertical eye movements may be attributed to a lesion in the tract from ri-MLF to the posterior commisure.

神経耳科学的所見が診断の手がかりとなった中脳水道周辺症候群の１例

Spontaneous abnormal eye movements are frequently caused by disease in the aqueduct of the midbrain and indicate the location of the lesion the at an early stage.We report here a case of Sylvian aqueduct syndrome in which neuro-otological findings became clues to the diagnosis. Our patient was a 54-year-old male with the chief complaint of unstable dizziness. He showed intermittent convergence nystagmus and upward gaze palsy. Hydrocephalus following non-tumoral aqueduct stenosis resulted in a lower inclination of the brainstem and caused such ocular symptoms. Structural changes could not be demonstrated in images at an early stage. Oculomotor abnormalties changed after a V-P shunt was placed and eventually disappeared.

Sylvian Aqueduct Syndrome. Chronology of Tumors in the Pineal Region in View of Ocular Movement

We experienced 21 cases of tumors (13 of pinealoma of the two-cell pattern and eight of tumors originating from the posterior part of the third ventricle). We carefully observed the eye movements of these patients during their respective clinical courses and found changes in abnormal eye movements along with remission following cobalt irradiation therapy or ventriculo-peritoneal shunt as well as with relapse on recurrence of tumors. From the neurotological viewpoint, we divided the development of these abnormal eye movements into four chronological stages. We emphasized the importance of the early diagnosis of tumors manifesting Sylvian aqueduct syndrome. Careful observation and analysis of eye movement will be a great help in making diagnoses as well as decisions for further examination and treatment.

Pseudo-Sylvian Aqueduct Syndrome

To the Editor.— Convergent nystagmus, paresis of upward gaze, and pupillary abnormalities are signs of the Sylvian aqueduct syndrome.1We wish to report an unusual case of myasthenic syndrome (Eaton-Lambert) demonstrating convergent nystagmus and pupillary abnormalities. Similar findings have been previously described in diseases affecting the dorsal midbrain. Our patient (who is a subject of a previous report2) is a 48-year-old man whose symptoms of lower extremity weakness and ptosis began in 1971. He was initially treated for myasthenia gravis. Because weakness persisted, electromyography was performed and the myasthenic syndrome was diagnosed. He began receiving guanidine, but chronic renal failure developed, necessitating long-term hemodialysis. At the present time he is receiving an experimental protocol of plasmapheresis, prednisone, azathioprine, and anticholinesterase medication. At the time of neuro-ophthalmologic examination, no anticholinesterase medication had been used for 12 hours. The examination showed no paresis of upward gaze. The pupils were sluggish

Global rostral midbrain dysfunction secondary to shunt malfunction in hydrocephalus.

Two cases of congenital hydrocephalus with shunt malfunction are described. Both patients presented with clinical syndromes suggestive of global rostral mesencephalic dysfunction, including the sylvian aqueduct syndrome, a parkinsonian-like state, and quadriparesis. Each had computed tomographic findings that showed marked dilatation of the lateral and 3rd ventricles, and both improved with revision of their shunts. The anatomical substrates of the clinical findings are reviewed. A discussion of the probable mechanism proposes that dilatation of the 3rd ventricle and rostral aqueduct sufficiently explains the entire syndrome. (Neurosurgery, 7: 322-325, 1980).

The Sylvian aqueduct syndrome and neurofibromatosis.

A 23-year-old man initially presented with the Sylvian aqueduct syndrome and subsequently developed cutaneous neurofibromata. The case is reported and the possibility that these represent manifestations of the same genetic abnormality is discussed.

A Case of Sylvian Aqueduct Syndrome Caused by Intra-Fourth Ventricle Tumor

We treated a rare case of the intra-fourth ventricle tumor which manifested the Sylvian aqueduct syndrome.A nine-year-old girl was admitted complaining of headache, vomiting and gait disturbance. Neurological examination on admission revealed papilledema, the right cerebellar sign and the truncal ataxia with no other neurological dysfunctions. The vertebral angiography and the Conray-ventriculography disclosed an intra-fourth ventricle tumor extending from the tumor of the cerebellar vermis. The tumor was removed subtotally as it was partially adherent to the outlet of the aqueduct. The histology was seen as astrocytoma of the piloid type. About 17 months after the operation the patient was readmitted complaining of headache and vomiting with the objective signs of convergence nystagmus, retractory nystagmus, upward gaze palsy and pupillary light reflex disturbance (the Sylvian aqueduct syndrome). A recurrence of the tumor was ruled out as a malfunction of the V-P shunt was evident. Conray-ventriculography revealed that the Sylvian aqueduct was remarkably dilated with a filling defect of the fourth ventricle. It might be considered that the outlet of the aqueduct was occluded by the rest of the tumor in addition to the malfunction of the V-P shunt. The ocular signs were gradually recovered after the reconstruction of the shunt; convergence nystagmus disappeared 6 months later, and upward gaze palsy at 12 months.Sylvian aqueduct syndrome is often observed in cases of pineal region tumor or a tumor in the posterior third ventricle; in such cases this syndrome is attributed to external compression of the midbrain.However, a dilated aqueduct caused by the obstructive hydrocephalus was demonstrated. Invasion of the tumor to the midbrain could be ruled out as ocular signs disappeared after the reconstruction of shunt.We conclude that the Sylvian aqueduct syndrome is caused by the cerebrospinal fluid pressure effect to the pretectal area, the posterior commissure and the periaqueductal area of the midbrain.

Abnormal Ocular Motility with Brainstem and Cerebellar Disorders

The disorders of ocular motility seen in association with brainstem or cerebellar disorders may point to rather specific anatomical or pathological correlations. Pontine gaze palsy reflects involvement of the pontine paramedian reticular formation. Internuclear ophthalmoplegia signifies a lesion in the medial longitudinal fasciculus. Skew deviation may result from a lesion anywhere in the posterior fossa. Ocular bobbing typically results from a pontine lesion. The Sylvian aqueduct syndrome is characteristic of involvement in the upper midbrain-pretectal region, usually a pinealoma. Cerebellar lesions may be manifested by gaze paresis, skew deviation, disturbances of saccadic or smooth pursuit movements, ocular myoclonus, or several characteristic forms of nystagmus. Familiarity with these disorders may be of great help to the physician dealing with a patient with a possible posterior fossa lesion.

Sylvian aqueduct syndrome as a sign of acute obstructive hydrocephalus in children.

Eight cases of obstructive hydrocephalus manifesting palsy of upward gaze and other features of the Sylvian aqueduct syndrome are reported. During the crisis of intracranial hypertension, all of them developed upward gaze palsy and variable abnormalities of the convergence mechanism such as paralysis, spasm, and convergence nystagmus. The frequent apparent blindness was probably related to gaze paralysis, since visual evoked responses were present. All these ocular abnormalities disappeared after shunting. Periaqueductal dysfunction on the basis of raised intracranial pressure is postulated as the possible mechanism for the above ocular manifestations. The 'setting sun' sign is frequently seen in infants and children with hydrocephalus and has been considered in the past to result from displacement of eyeballs by pressure from the orbital roof plate. Our observations would suggest periaqueductal dysfunction rather than the mechanical displacement as the possible mechanism for this sign.

Periaqueductal dysfunction (the Sylvian aqueduct syndrome): a sign of hydrocephalus?

A patient with hydrocephalus due to aqueductal occlusion is described in whom the Sylvian aqueduct syndrome appeared during a sudden increase in intracranial pressure. The ocular signs resolved completely when the hydrocephalus was relieved. Marked dilatation of the posterior part of the third ventricle and of the rostral aqueduct with axial displacement of these structures was demonstrated radiologically. It is suggested that the ocular signs in this case were the result of periaqueductal dysfunction due to assimilation and dilatation of the aqueduct, with secondary tentorial block. This abnormality may be the cause of the similar abnormalities commonly found in noncommunicating hydrocephalus in both infants and adults.

Paroxysmal vertical ocular dyskinesia.

Paroxysmal vertical ocular dyskinesia of a previously undescribed nature is reported in a 42-year-old woman with demyelinating disease, who was affected with a myelopathy, bilateral amblyopia, and a modified sylvian aqueduct syndrome. Electroencephalography, electronystagmography, and cinematography techniques were used to study this phenomenon. This eye movement disorder is distinct from, but related to, other forms of ocular dyskinesia.

Clinical Methods of Neuro-Ophthalmologic Examinations

The second edition of this text has long been awaited since the 1946 edition has been out of print for many years. The book has the most complete discussion of optokinetic nystagmus available in any text. Topical diagnosis of 3 nerve palsies is presented in the most thorough fashion of any available text. The differential diagnosis of anisocoria is handled quite well. Excellent sections on the chiasm, nystagmus, sylvian aqueduct syndrome, and gaze movements are included, besides being a good source of eponyms. The main criticism of the second edition is the omissions. Many subjects of current neuro-ophthalmologic interest are not included. However, although restricted in size, there are new sections on electromyography, electroretinography, and pupillography. In summary, although not a complete reference source of neuro-ophthalmology, this is a valuable textbook.

Clinical Methods of Neuro-Ophthalmologic Examinations.

The second edition of this text has been long awaited as the 1946 edition has been extinct for many years. The text has many good points which warrant its thorough digestion by ophthalmologists and neurologists. Strong points include these: (1) It has the most complete discussion of optokinetic nystagmus available in any text. (2) The topical diagnosis of III nerve palsies is presented in the most thorough fashion of any available text. (3) The differential diagnosis of anisocoria is quite well handled. (4) There are excellent sections on the chiasm, nystagmus sylvian aqueduct syndrome, and gaze movements. (5) It is an excellent source of eponyms. The main criticism against this second edition would be the omissions. Many subjects of current neuro-ophthalmologic interest are not included. Thus, there is no discussion of cerebrovascular insufficiency. Although one and one-half pages are devoted to ophthalmodynamometry, there is no mention of this technique for