Sedative stereoencephalotomy: fornicotomy, upper mesencephalic reticulotomy and postero-medial hypothalamotomy

Structural hyperconnectivity of the subthalamic area with limbic cortices underpins anxiety and impulsivity in Tourette syndrome

Tourette syndrome (TS) is a neurodevelopmental disorder characterized by motor and vocal tics, which is often associated with psychiatric comorbidities. Dysfunction of basal ganglia pathways might account for the wide spectrum of symptoms in TS patients. Although psychiatric symptoms may be related to limbic networks, the specific contribution of different limbic structures remains unclear. We used tractography to investigate cortical connectivity with the striatal area (caudate, putamen, core and shell of the nucleus accumbens), the subthalamic nucleus (STN), and the adjacent medial subthalamic region (MSR) in 58 TS patients and 35 healthy volunteers. 82% of TS patients showed psychiatric comorbidities, with significantly higher levels of anxiety and impulsivity compared to controls. Tractography analysis revealed significantly increased limbic cortical connectivity of the left MSR with the entorhinal (BA34), insular (BA48), and temporal (BA38) cortices in TS patients compared to controls. Furthermore, we found that left insular-STN connectivity was positively correlated with impulsivity scores for all subjects and with anxiety scores for all subjects, particularly for TS. Our study highlights a heterogenous modification of limbic structure connectivity in TS, with specific abnormalities found for the subthalamic area. Abnormal connectivity with the insular cortex might underpin the higher level of impulsivity and anxiety observed in TS.

The historical evolution of the fornix and its terminology: a review

The historical evolution of the fornix has not been sufficiently reviewed in the literature. In this article, we follow this evolution from the first mention of the fornix in animal dissections of the second century AD, to the legalization of cadaver dissection in the 1300 s, to the introduction of neural staining techniques and the microscope in the seventeenth century, to today. We summarize the focus of fornix studies on memory to reveal its relationship with the hippocampus. We then cover the detection of the fornix and its neural connections noninvasively with the advancement of radiological imaging techniques. Finally, we discuss the prominence of the fornix as a target for deep brain stimulation in Alzheimer's disease and post-traumatic brain injury memory disorders.

[Rolf Hassler: from leucotomy to stereotaxy]

Rolf Hassler is one of the most renowned German specialists in psychiatry, neurology and neuroanatomy. Hassler's career exemplifies medicine as scientific endeavor. Relaying on an expertise in neuroanatomy gained at Oscar and Cecile Vogt's Kaiser Wilhelm Institute, especially regarding the structure of the thalamus, Hassler enabled Freiburg University's neurosurgery clinic the invention of stereotactic "stepped leucotomy" and established thalamotomy internationally in a leading way. While directing the Neuroanatomical/Neurobiological department of the Max Planck Institute for Brain Research from 1959 until 1982, Hassler continued to study the effects of stimulation and targeted subcortical electrocoagulation in the cat brain. The Freiburg trained neurosurgeon Gert Dieckmann helped Hassler to apply the newly gained knowledge for the stereotactic therapy of torticollis, tics and obsessions and compulsions. The use however of thalamotomy also as a surgical therapy for aggressiveness in children, mainly during the late 1960s and early 1970s, is starting to provoke public criticism. Contrary however to the accusation of a medicine shaped by Nazi ideology into a "science without humanity", Hasslers career reveals a problematic intrinsic to medicine: the together of "art of healing and science".

Fornicotomy for the Treatment of Epilepsy: An Examination of Historical Literature in the Setting of Modern Operative Techniques

Fornicotomy has been used to treat intractable temporal lobe epilepsy with mixed success historically; however, modern advances in stereotactic, neurosurgical, and imaging techniques offer new opportunities to target the fornix with greater precision and safety. In this review, we discuss the historical uses and quantify the outcomes of fornicotomy for the treatment of temporal lobe epilepsy, highlight the potential mechanisms of benefit, and address what is known about the side effects of the procedure. We find that fornicotomy, with or without anterior commissurotomy, resulted in 61% (83/136) of patients having some seizure control benefit. We discuss the potential operative approaches for targeting the fornix, including laser ablation and the use of focused ultrasound ablation. More work is needed to address the true efficacy of fornicotomy in the modern surgical setting. This review is intended to serve as a framework for developing this approach.

Stereotactic operation in behaviour disorders. Amygdalotomy and hypothalamotomy

After a survey of the anatomical and physiological basis of operative treatment of behaviour disorders by stereotactic lesions in the amygdala and the posterior medial hypothalamus the author describes his own experiences with 603 operations for control of conservatively untreatable aggressiveness. In 481 cases bilateral amygdalotomies and in 122 mostly secondary posteromedian hypothalamotomies have been performed. Initially excellent or moderate improvement was achieved in 76%. After a follow-up of more than three years this figure only slightly decreased to 70%. The group of patients who did not positively respond (30%) needs further study to discover the reasons for failure.

The neural basis of aggression and its treatment by psychosurgery

The limbic system and its connections provide the neural basis for aggressive behaviour. Violent individuals may differ quantitively or qualitively from normal. Many of the latter suffer from epilepsy. In some the epileptiform discharges from the amygdala can only be recorded using depth electrodes. It can be taken that the control of abnormal degrees of violent behaviour is now possible. Should such operations be used? If so who should have them? What preacutions need to be taken that such operations are not abused? How can informed consent be obtained? The development of new surgical techniques make these questions pertinent if not urgent.

Stereotactic hypothalamotomy for behaviour disorders

Posterior hypothalamotomy is a relatively simple stereotactic procedure. The radiological determination of the target and its physiological corroboration by electrical stimulation are accurate. The lesions have always been made in the site of maximum sympathetic response. In this respect, the cardiovascular changes (hypertension and tachycardia), which are always elicited from a more restricted area, are of particular importance. Depth recordings, however, have been less useful. Undesirable side-effects, if present, were mild and transitory. There was no postoperative intelligence deficit, at least with the standard tests.

Results of stimulation and destruction of the posterior hypothalamus in man

✓ Autonomic and somatomotor responses to electrical stimulation of the posterior hypothalamus are reported in 51 patients with pathologically aggressive behavior. The stimulated area causing rise in blood pressure, tachycardia, and maximal pupillary dilatation lies in the posteromedial hypothalamus, more than 1 mm and less than 5 mm lateral to the lateral wall of the third ventricle, occupying a triangle formed by the midpoint of the intercommissural line, the rostral end of the aqueduct, and the anterior border of the mammillary body. Electrical stimulation of this (ergotropic) triangle resulted in desynchronization of the electroencephalogram (EEG) with hippocampal theta waves, or diffuse irregular delta waves of high voltage.

Cases with violent behavior showed higher plasma levels of non-esterified fatty acids (NEFA) in the fasting stage; these were markedly elevated by electrical stimulation of the ergotropic triangle.

Points in the ergotropic triangle where signs of sympathetic discharge were most marked were electrocauterized bilaterally. This procedure produced marked calming effects (95% of the cases) during the follow-up period of more than 2 years. Postoperatively there was a tendency to a decrease in sympathicotonia or an increase in parasympathicotonia. The follow-up plasma level of NEFA was found to have decreased to approximately the normal value.