ACTA NEUROCHIRURGICA 9 by Springer-Verlag 1979
Acta Neurochirurgica 46, 243--257 (1979)
Departments of Neurosurgery, Neurology, Neuroradiology and Nuclear Medicine, Aarhus Kommunehospital, Aarhus, Denmark
Acquired H y d r o c e p h a l u s II. Diagnostic and Prognostic Value of Quantitative Isotope Ventriculography (QIV), Lumbar Isotope Cisternography (LIC), Pneumoencephalography, and Continuous Intraventricular Pressure Recording (GIP) By
F. Jensen and F. T. Jensen With 1 Figure
Summary The diagnostic and prognostic values of quantitative isotope ventriculography (QIV), lumbar isotope cisternography (LIC), pneumoencephalography (PEG), and continuous intraventricular pressure recording (CIP) were assessed on the basis of the clinical course in 160 patients suspected of having acquired hydrocephalus. The diagnostic value of a given method is defined as its reliability in the diagnosis of hydrocephalus. The reliability in the selection of hydrocephalic patients who will improve on shunt operation is designated as the prognostic value of the method concerned. As the diagnoses are based on isotopic procedures, the diagnostic values of these procedures cannot be assessed. QIV is of greater prognostic value than the other methods of examination. The presence of plateau waves in CIP is a rare, but prognostically valuable sign. The prognostic value of B waves is also good, whereas their diagnostic value is slight. Both from diagnostic and prognostic points of view, PEG is of less value in communicating hydrocephalus on account of the many false findings.
Introduction The value of a given method of examination depends on its reliability as an aid in the diagnosis (diagnostic value) and in the selection of patients who will improve on relevant treatment (prognostic value). During the last two decades, the principles of examination used in the diagnostic and prognostic evaluation of hydrocephalus in adults, including normal-pressure hydro0001-6268/79/0046/0243/$ 03.00
244
F. Jensen and F. T. jensen:
cephalus (NPH), have been the subject of ardent discussion. In the first studies on hydrocephalus in adults, pneumoencephalography (PEG) was used in the diagnosis of cases requiring treatment 1, Isotopic procedures were first used in hydrocephalus by Bell 8 in 1959 and by Atkinson et al. ~ in 1961. Not until the scintigraphic studies performed by Bannister e t a / . 6. 7 and by Di Chiro et aI. 19. 20, 21 was cisternography specifically used in patients suspected of communicating hydrocephalus (CH). Isotope ventriculography was first described by Di Chiro et al. 19, 20, Glasauer 24, Hammo& and Milhorat 2s. 42, Jensen et al. 15, 1~, 31, 32, Knoetgen et al. 3v, and Wolpert et cd. 54. This method, particularly in its quantitative form, is used in the disclosure of both CH and obstructive hydrocephalus (OH). An increased intraventricular pressure has previously been used as a criterion of hydrocephalus requiring treatment, but in hydrocephalus with normal intracranial pressure (ICP) this method cannot be used. Continuous intraventricular pressure recording (CIP), introduced by Lundberg ~9 in 1960, was a valuable additional aid in the diagnosis of hydrocephalus. The purpose of this analysis was to assess the value of quantitative isotope ventriculography (QIV), lumbar isotope cisternography (LIC), PEG, and CIP as diagnostic methods in hydrocephalus in adults. The clinical results obtained in the series of patients studied have been reported in a previous study ~3, and here used in the evaluation of the diagnostic and prognostic value of the methods. M e t h o d and Material In QIV, scintigrams are taken in the anteroposterior and lateral projections at 1, 3, 6, 24, and 48 hours after the intraventricular injection of about 50 ~tCi laI-albumin. Based on the actual count rates corrected for physical decay and background radiation, a curve for the retention of activity in the measuring field is plotted (Fig. 1). From the first part of the curve the half-life (T 89 is calculated. Furthermore, calculations are performed of the 24-hours value of the amount of activity retained 24 hours after the injection, and of the T-50 value, i.e., the time elapsing until 50% of the activity has left the head. All three parameters are expressions of the excretion of activity from the measuring field. Under normal conditions, the isotope has left the ventricular system within 24 hours of the injection, and the retention curve shows normal excretion (Table 1). In OH, no activity is seen in the posterior fossa during the period of isotope study. For a diagnosis of CH, pathological scintigrams or delayed excretion of activity from the head, or both, are required. In pathological scintigrams intraventricular retention of the activity is seen for 24 hours or more, often associated
Acquired Hydrocephalus. II.
245
Table 1. Parameters of the Retention Curve
Normal Uncertain Delayed
T 89 hours
24-hour value ~
T-50 hours
22
50
Acta Neurochirurgica 46, 243--257 (1979)
Departments of Neurosurgery, Neurology, Neuroradiology and Nuclear Medicine, Aarhus Kommunehospital, Aarhus, Denmark
Acquired H y d r o c e p h a l u s II. Diagnostic and Prognostic Value of Quantitative Isotope Ventriculography (QIV), Lumbar Isotope Cisternography (LIC), Pneumoencephalography, and Continuous Intraventricular Pressure Recording (GIP) By
F. Jensen and F. T. Jensen With 1 Figure
Summary The diagnostic and prognostic values of quantitative isotope ventriculography (QIV), lumbar isotope cisternography (LIC), pneumoencephalography (PEG), and continuous intraventricular pressure recording (CIP) were assessed on the basis of the clinical course in 160 patients suspected of having acquired hydrocephalus. The diagnostic value of a given method is defined as its reliability in the diagnosis of hydrocephalus. The reliability in the selection of hydrocephalic patients who will improve on shunt operation is designated as the prognostic value of the method concerned. As the diagnoses are based on isotopic procedures, the diagnostic values of these procedures cannot be assessed. QIV is of greater prognostic value than the other methods of examination. The presence of plateau waves in CIP is a rare, but prognostically valuable sign. The prognostic value of B waves is also good, whereas their diagnostic value is slight. Both from diagnostic and prognostic points of view, PEG is of less value in communicating hydrocephalus on account of the many false findings.
Introduction The value of a given method of examination depends on its reliability as an aid in the diagnosis (diagnostic value) and in the selection of patients who will improve on relevant treatment (prognostic value). During the last two decades, the principles of examination used in the diagnostic and prognostic evaluation of hydrocephalus in adults, including normal-pressure hydro0001-6268/79/0046/0243/$ 03.00
244
F. Jensen and F. T. jensen:
cephalus (NPH), have been the subject of ardent discussion. In the first studies on hydrocephalus in adults, pneumoencephalography (PEG) was used in the diagnosis of cases requiring treatment 1, Isotopic procedures were first used in hydrocephalus by Bell 8 in 1959 and by Atkinson et al. ~ in 1961. Not until the scintigraphic studies performed by Bannister e t a / . 6. 7 and by Di Chiro et aI. 19. 20, 21 was cisternography specifically used in patients suspected of communicating hydrocephalus (CH). Isotope ventriculography was first described by Di Chiro et al. 19, 20, Glasauer 24, Hammo& and Milhorat 2s. 42, Jensen et al. 15, 1~, 31, 32, Knoetgen et al. 3v, and Wolpert et cd. 54. This method, particularly in its quantitative form, is used in the disclosure of both CH and obstructive hydrocephalus (OH). An increased intraventricular pressure has previously been used as a criterion of hydrocephalus requiring treatment, but in hydrocephalus with normal intracranial pressure (ICP) this method cannot be used. Continuous intraventricular pressure recording (CIP), introduced by Lundberg ~9 in 1960, was a valuable additional aid in the diagnosis of hydrocephalus. The purpose of this analysis was to assess the value of quantitative isotope ventriculography (QIV), lumbar isotope cisternography (LIC), PEG, and CIP as diagnostic methods in hydrocephalus in adults. The clinical results obtained in the series of patients studied have been reported in a previous study ~3, and here used in the evaluation of the diagnostic and prognostic value of the methods. M e t h o d and Material In QIV, scintigrams are taken in the anteroposterior and lateral projections at 1, 3, 6, 24, and 48 hours after the intraventricular injection of about 50 ~tCi laI-albumin. Based on the actual count rates corrected for physical decay and background radiation, a curve for the retention of activity in the measuring field is plotted (Fig. 1). From the first part of the curve the half-life (T 89 is calculated. Furthermore, calculations are performed of the 24-hours value of the amount of activity retained 24 hours after the injection, and of the T-50 value, i.e., the time elapsing until 50% of the activity has left the head. All three parameters are expressions of the excretion of activity from the measuring field. Under normal conditions, the isotope has left the ventricular system within 24 hours of the injection, and the retention curve shows normal excretion (Table 1). In OH, no activity is seen in the posterior fossa during the period of isotope study. For a diagnosis of CH, pathological scintigrams or delayed excretion of activity from the head, or both, are required. In pathological scintigrams intraventricular retention of the activity is seen for 24 hours or more, often associated
Acquired Hydrocephalus. II.
245
Table 1. Parameters of the Retention Curve
Normal Uncertain Delayed
T 89 hours
24-hour value ~
T-50 hours
22
50
