Cosmetic aspects and protection of the brain from mechanical injuries are the most common indications for the repair of traumatic and operative cranial defects. We suggest two additional indications: Cranioplasty is not only important in the treatment of space-occupying fluid cysts, but also in preventing or overcoming hemisphere collapse with its resultant displacement of the midline structures. This complication was almost exclusively found in patients subjected to extensive lateral craniotomies and also led to psycho-organic syndromes with disturbances of mood and drive. In few cases a crippling hemiparesis and epileptiform fits were also present. The recovery of the patients was almost complete after the repair of the cranial defect. Clinical improvement was due to restitution of physiological intracranial pressure state and re-expansion of the cerebral hemispheres as could be shown by computer tomography. The operative procedure of auto-, homo- and heteroplastic cranioplasty is described, with particular emphasis on the new technique with acrylic plastic, developed by the authors.

Transcranial Doppler sonography (TCD) is a simple method to detect a right-to-left cardiac shunt, although standardized procedures do not exist. In this study 69 patients were tested according to predetermined criteria and procedures (cluster of > 10 microbubbles, duration between injection in the cubital vein and detection in the middle cerebral artery [MCA] < or = 10 sec). Agitated saline solution was compared to oxypolygelatine, a plasma volume expander, as contrast media. Valsalva's maneuver and coughing were used to provoke right-to-left cardiac shunting, detected by TCD, transthoracic echocardiography (TTE), and transesophageal echocardiography (TEE). Oxypolygelatine caused a significantly higher number of microbubbles in the right atrium and MCA than did the saline solution, leading to a greater diagnostic reliability of TCD (paired t test, p < 0.001). Coughing did not provoke right-to-left cardiac shunts (x2 analysis, p < 0.001). The technique used for carrying out Valsalva's maneuver was important for the detection of right-to-left cardiac shunts. Twenty-five right-to-left shunts were diagnosed with TCD and 18 with TTE (36 vs 26%; x2 analysis, p = 0.1). The findings indicate that TCD when properly done is highly sensitive and specific for the diagnosis of right-to-left cardiac shunts.

The cross-sectional area of the internal jugular vein was measured in 8 normal healthy subjects and in two patients having AV malformations in the internal carotid circulation using a linear-array scanner with facilities for computerised planimetry. Mean blood flow velocity was measured at the same site of the vessel by means of continuous-wave Doppler flowmeter. The product of the two values was considered to indicate volume flow. The mean value for bilateral flow was 656 +/- 113 ml/min in the normal series. In the two patients the values were 1 331 ml/min and 860 ml/min respectively.

Description of a TCD test designed for the clinical investigation of cerebral autoregulation. The Doppler shift frequency of the middle cerebral artery is recorded using of a transducer fixed to the patient's head by an elastic ribbon and a ball joint type probe-holder, and on-line digitally analysed to calculate the TCD flow index (signal power times velocity). Blood pressure is measured every 30 seconds at the right index hold at the level of the heart, using a special sphygmomanometer. The patient sits on a foot-stool. After 1.5 minutes of measurement he rises to remain in upright position for another 2 minutes. The flow index normalised to its average over the sitting period quantitatively indicates the evolution of volume flow brought about by the change of the body position. The change in arterial blood pressure is off-line calculated from its periodic measurements. In a pilot study this test has been successfully used in 30 healthy volunteers and 2 patients suffering from orthostatic dysregulation of blood pressure.

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