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Can sonographic measurement of optic nerve sheath diameter be used to detect raised intracranial pressure in patients with tuberculous meningitis? A prospective observational study.

Sangani SV, Parikh S - Indian J Radiol Imaging (2015 Apr-Jun)

Bottom Line: In total, the optic nerve sheath diameters of 25 adults with confirmed TBME were measured.These measurements were compared with 120 control patients.The evaluation of the ONSD is a simple non-invasive and potentially useful tool in the assessment of adults suspected of having TBME.

View Article: PubMed Central - PubMed

Affiliation: Department of Emergency Medicine, BJ Medical College, Civil Hospital, Ahmedabad, Gujarat, India.

ABSTRACT

Unlabelled: CNS Tuberculosis can manifest as meningitis, arachnoiditis and a tuberculoma. The rupture of a tubercle into the subarachnoid space leads to Tuberculosis Meningitis (TBME); the resulting hypersensitivity reaction can lead to an elevation of the intracranial pressure and hydrocephalus. While bedside optic nerve sheath diameter (ONSD) ultrasonography (USG) can be a sensitive screening test for elevated intracranial pressure in adult head injury, little is known regarding ONSD measurements in Tuberculosis Meningitis.

Objectives: The aim of this study was to determine whether patients with TBME had dilation of the optic nerve sheath, as detected by ocular USG performed in the emergency department (ED).

Materials and methods: We conducted a prospective, observational study on adult ED patients with suspected TBME. Patients underwent USG measurements of the optic nerve followed by MRI. The ONSD was measured 3 mm behind the globe in each eye. MRI evidence of basilar meningeal enhancement and any degree of hydrocephalus was suggestive of TBME. Those patients without evidence of hydrocephalus subsequently underwent a lumbar puncture to confirm the diagnosis. Exclusion criteria were age less than 18 and obvious ocular pathology. In total, the optic nerve sheath diameters of 25 adults with confirmed TBME were measured. These measurements were compared with 120 control patients.

Results: The upper limit of normal ONSD was 4.37 mm in control group. Those patients with TBME had a mean ONSD of 5.81 mm (SD 0.42). These results confirm that patients with tuberculosis meningitis have an ONSD in excess of the control data (P < 0.001).

Conclusion: The evaluation of the ONSD is a simple non-invasive and potentially useful tool in the assessment of adults suspected of having TBME.

No MeSH data available.


Related in: MedlinePlus

Showing abnormally increased optic nerve sheath diameter of 6.2 mm (distance B)
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Figure 3: Showing abnormally increased optic nerve sheath diameter of 6.2 mm (distance B)

Mentions: The ONSD was measured 3 mm posterior to the globe for both eyes in each patient [Figure 2]. The two measurements were averaged. An average ONSD of 5 mm or greater was considered abnormal [Figure 3].


Can sonographic measurement of optic nerve sheath diameter be used to detect raised intracranial pressure in patients with tuberculous meningitis? A prospective observational study.

Sangani SV, Parikh S - Indian J Radiol Imaging (2015 Apr-Jun)

Showing abnormally increased optic nerve sheath diameter of 6.2 mm (distance B)
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4419427&req=5

Figure 3: Showing abnormally increased optic nerve sheath diameter of 6.2 mm (distance B)
Mentions: The ONSD was measured 3 mm posterior to the globe for both eyes in each patient [Figure 2]. The two measurements were averaged. An average ONSD of 5 mm or greater was considered abnormal [Figure 3].

Bottom Line: In total, the optic nerve sheath diameters of 25 adults with confirmed TBME were measured.These measurements were compared with 120 control patients.The evaluation of the ONSD is a simple non-invasive and potentially useful tool in the assessment of adults suspected of having TBME.

View Article: PubMed Central - PubMed

Affiliation: Department of Emergency Medicine, BJ Medical College, Civil Hospital, Ahmedabad, Gujarat, India.

ABSTRACT

Unlabelled: CNS Tuberculosis can manifest as meningitis, arachnoiditis and a tuberculoma. The rupture of a tubercle into the subarachnoid space leads to Tuberculosis Meningitis (TBME); the resulting hypersensitivity reaction can lead to an elevation of the intracranial pressure and hydrocephalus. While bedside optic nerve sheath diameter (ONSD) ultrasonography (USG) can be a sensitive screening test for elevated intracranial pressure in adult head injury, little is known regarding ONSD measurements in Tuberculosis Meningitis.

Objectives: The aim of this study was to determine whether patients with TBME had dilation of the optic nerve sheath, as detected by ocular USG performed in the emergency department (ED).

Materials and methods: We conducted a prospective, observational study on adult ED patients with suspected TBME. Patients underwent USG measurements of the optic nerve followed by MRI. The ONSD was measured 3 mm behind the globe in each eye. MRI evidence of basilar meningeal enhancement and any degree of hydrocephalus was suggestive of TBME. Those patients without evidence of hydrocephalus subsequently underwent a lumbar puncture to confirm the diagnosis. Exclusion criteria were age less than 18 and obvious ocular pathology. In total, the optic nerve sheath diameters of 25 adults with confirmed TBME were measured. These measurements were compared with 120 control patients.

Results: The upper limit of normal ONSD was 4.37 mm in control group. Those patients with TBME had a mean ONSD of 5.81 mm (SD 0.42). These results confirm that patients with tuberculosis meningitis have an ONSD in excess of the control data (P < 0.001).

Conclusion: The evaluation of the ONSD is a simple non-invasive and potentially useful tool in the assessment of adults suspected of having TBME.

No MeSH data available.


Related in: MedlinePlus