Validation of the optic nerve sheath response to changing cerebrospinal fluid pressure: ultrasound findings during intrathecal infusion tests

1997 ◽  
Vol 87 (1) ◽  
pp. 34-40 ◽  
Author(s):  
Hans-Christian Hansen ◽  
Knut Helmke
Keyword(s):  
Cerebrospinal Fluid ◽  
Optic Nerve ◽  
Fluid Pressure ◽  
Optic Nerve Sheath ◽  
Variable Pressure ◽  
Content Type ◽  
Csf Pressure ◽  
Nerve Sheath ◽  
Intrathecal Infusion ◽  
Fine Print

✓ Raised intracranial pressure leads to increased pressure around the optic nerve (ON), which underlies the formation of papilledema and the enlargement of the dural optic nerve sheath (ONS). In clinical practice, the presence of widened ONSs is demonstrable on neuroimaging, but their relationship to cerebrospinal fluid (CSF) pressure remains unknown. The authors investigated the ONS response to pressure during CSF absorption studies in 12 patients undergoing neurological testing. The ONS diameter was evaluated by serial B-mode ultrasound scans of the anterior ON near its entry into the globe. All patients tested showed ONS diameter changes that exhibited covariance with the alteration of lumbar CSF pressure and were completely reversible during the infusion tests. The maximum difference in ONS diameter between baseline and peak pressure conditions was 1.8 mm on average (range 0.7–3.1 mm), corresponding to an average ONS diameter variation of 45% (range 15–89%). Regression analysis yielded a linear covariance between ONS diameter and CSF pressure with different slopes across subjects (0.019–0.071 mm/mm Hg, mean r = 0.78). However, this linear relationship was only present within a CSF pressure interval. This interval differed between patients: ONS dilation commenced at pressure thresholds between 15 mm Hg and 30 mm Hg and in some patients saturation of the response (constant ONS diameter) occurred between 30 mm Hg and 40 mm Hg. With a single exception, definitely enlarged ONS diameters (> 5 mm) were present when CSF pressure exceeded levels of 30 mm Hg. Retrospectively, discrimination between normal and elevated outflow resistance was possible on the basis of the ONS response to intrathecal infusion alone. It is concluded that the human ONS has sufficient elasticity to allow a detectable dilation in response to intracranial hypertension. Because of a variable pressure—diameter relationship, the subarachnoid pressure cannot be predicted exactly by single scans. Therefore, the clinical relevance of this method relies on the demonstration of pathologically enlarged sheaths or ongoing enlargement on serial ultrasonography studies.

Surgical management of meningiomas involving the optic nerve sheath

2004 ◽  
Vol 101 (6) ◽  
pp. 951-959 ◽  
Author(s):  
Uta Schick ◽  
Uwe Dott ◽  
Werner Hassler
Keyword(s):  
Optic Nerve ◽  
Postoperative Radiotherapy ◽  
Visual Outcome ◽  
Tumor Location ◽  
Optic Nerve Sheath ◽  
Optic Canal ◽  
Content Type ◽  
Nerve Sheath ◽  
Fine Print

Object. The management of optic nerve sheath meningiomas (ONSMs) remains controversial but includes surgery, radiotherapy, and plain observation. Surgery is often thought to result in postoperative blindness. The authors report on a large series of patients surgically treated for ONSM, with an emphasis on the visual outcome. Methods. Seventy-three patients with ONSMs who had undergone surgery between 1991 and 2002 were retrospectively analyzed. The standard surgical approach consisted of pterional craniotomy, intradural (54 patients) or extradural (10 patients) unroofing of the optic canal, or a combined procedure (seven patients). Thirty-two tumors demonstrated extension through the optic canal. Twenty-nine tumors reached the chiasm or contralateral side. Patients with intraorbital flat tumors should undergo radiotherapy instead of surgery. Those with a large intraorbital mass and no useful vision should undergo surgery. Tumors extending intracranially through the optic canal are amenable to decompression of the optic canal and resection of the intracranial portion. The follow-up period was a mean 45.4 months (range 6–144 months). Ten patients underwent postoperative radiotherapy. Visual acuity was not significantly influenced by surgery but did become worse with a longer duration of preoperative symptoms and a longer follow-up period. A tumor location in the optic canal was another negative factor. Radiotherapy preserved vision in five of 10 cases. Conclusions. The loss of vision in patients with ONSM is only a matter of time. In patients with good vision the role of radiotherapy becomes more important. Surgery is recommended for intracranial tumors to prevent contralateral extension.

Intraocular and optic nerve sheath hemorrhage in cases of sudden intracranial hypertension

1974 ◽  
Vol 41 (2) ◽  
pp. 160-166 ◽  
Author(s):  
Paul J. Muller ◽  
John H. N. Deck
Keyword(s):  
Optic Nerve ◽  
Intracranial Hypertension ◽  
Venous Hypertension ◽  
Optic Nerve Sheath ◽  
Consistent Finding ◽  
Content Type ◽  
Nerve Sheath ◽  
Intraocular Hemorrhage ◽  
Central Retinal Vein ◽  
Fine Print

✓ The eyes of 23 patients with sudden intracranial hypertension were studied at post-mortem. Intraocular hemorrhage had occurred in 37% and optic nerve sheath hemorrhage in 87%. Expansion of the optic nerve sheath, particularly the fusiform retrobulbar portion, was a consistent finding. The subdural space of the optic nerve sheath bore the brunt of the hemorrhage which sometimes communicated with perivascular intradural hemorrhages. Optic nerve sheath hemorrhage is shown to result from rupture of dural and bridging vessels of the optic nerve sheath; this we conclude is subsequent to optic nerve sheath dilatation caused by the transmission of intracranial pressure through the subarachnoid communication between the optic nerve sheath and the intracranial cavity. Intraocular hemorrhage is the result of retinal venous hypertension and rupture brought on by obstruction of both the central retinal vein and the retinochoroidal anastomosis.

Intracranial pressure following optic nerve decompression for benign intracranial hypertension

1981 ◽  
Vol 55 (3) ◽  
pp. 453-456 ◽  
Author(s):  
Andrew H. Kaye ◽  
J. E. K. Galbraith ◽  
John King
Keyword(s):  
Optic Nerve ◽  
Intracranial Pressure ◽  
Intracranial Hypertension ◽  
Continuous Recording ◽  
Optic Nerve Sheath ◽  
Benign Intracranial Hypertension ◽  
Content Type ◽  
Nerve Sheath ◽  
Before And After ◽  
Fine Print

✓ The authors report the case of a patient with benign intracranial hypertension and severe papilledema, who underwent surgery for bilateral optic nerve sheath decompression. No change in the intracranial pressure (ICP) was seen during continuous recording performed before and after the operation. This case supports the contention that the decrease in papilledema and the visual improvements seen following this operation are more likely to be due to decrease in optic nerve sheath pressure than to a generalized decrease in ICP, as suggested by other authors.

Primary optic nerve sheath meningiomas

1989 ◽  
Vol 70 (1) ◽  
pp. 37-40 ◽  
Author(s):  
W. Craig Clark ◽  
Charles S. Theofilos ◽  
James C. Fleming
Keyword(s):  
Optic Nerve ◽  
Management Strategy ◽  
Optic Nerve Sheath ◽  
Definitive Treatment ◽  
Optimal Management ◽  
Tumor Removal ◽  
Content Type ◽  
Nerve Sheath ◽  
Optic Nerve Sheath Meningioma ◽  
Fine Print

✓ Between 1979 and 1987 the authors treated nine cases of primary optic nerve sheath meningioma. The definitive treatment for these lesions is surgical resection, although no single best plan for optimal management has been determined. The data indicate that only small anterior tumors may be removed with preservation of useful vision. With posterior circumferential tumors, there have been no cases of tumor removal with preservation of vision. A management strategy directed toward preservation of vision is discussed.

Visual changes after gamma knife surgery for optic nerve tumors

2005 ◽  
Vol 102 (Special_Supplement) ◽  
pp. 143-146 ◽  
Author(s):  
Yang Kwon ◽  
Jun Seok Bae ◽  
Jae Myung Kim ◽  
Do Hee Lee ◽  
Soon Young Kim ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Gamma Knife ◽  
Gamma Knife Surgery ◽  
Optic Glioma ◽  
Content Type ◽  
Nerve Sheath ◽  
Optic Nerve Sheath Meningioma ◽  
Optic Nerve Tumors ◽  
Visual Changes ◽  
Fine Print

✓ Tumors involving the optic nerve (optic glioma, optic nerve sheath meningioma) are benign but difficult to treat. Gamma knife surgery (GKS) may be a useful treatment. The authors present data obtained in three such cases and record the effects of GKS.

Continuous simultaneous monitoring of intraventricular and cervical subarachnoid cerebrospinal fluid pressure to indicate development of cerebral or tonsillar herniation

1970 ◽  
Vol 33 (2) ◽  
pp. 145-150 ◽  
Author(s):  
Gary E. Kaufmann ◽  
Kemp Clark
Keyword(s):  
Cerebrospinal Fluid ◽  
Pressure Gradient ◽  
Fluid Pressure ◽  
Cerebrospinal Fluid Pressure ◽  
Continuous Recording ◽  
Tonsillar Herniation ◽  
Content Type ◽  
Fine Print ◽  
Made In

✓ A simultaneous continuous recording of intraventricular and cervical subarachnoid cerebrospinal fluid pressures was made in each of 20 patients who were comatose or decerebrate. All patients with a pressure gradient greater than 10 mm Hg died and at autopsy were found to have evidence of severe transtentorial and/or tonsillar herniation.

The effects of raised ICP on lymph flow in the cervical lymphatic trunks in cats

1984 ◽  
Vol 60 (3) ◽  
pp. 577-581 ◽  
Author(s):  
James A. Love ◽  
Ronald A. Leslie
Keyword(s):  
Cerebrospinal Fluid ◽  
Steady State ◽  
Subarachnoid Space ◽  
Lymphatic System ◽  
Cranial Nerves ◽  
Lymph Flow ◽  
Content Type ◽  
Large Molecules ◽  
Csf Pressure ◽  
Fine Print

✓ Lymph was collected from cervical lymphatic trunks of anesthetized cats under conditions of normal cerebrospinal fluid (CSF) pressure and again when the CSF pressure was elevated by infusing artificial CSF into the subarachnoid space at the cisterna magna. There was an immediate increase in lymph flow on initiation of the CSF infusion, but this increase was not maintained although the CSF infusion continued. Lymph protein concentrations fell when the CSF infusion started and remained depressed while the infusion of CSF continued. It is postulated that under steady-state conditions much of the CSF leaving the subarachnoid space via the cranial nerves enters the capillaries from the extravascular spaces, and that large molecules from the CSF, such as proteins, return to the blood via the lymphatic system.

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