| Bilateral cingulotomy | |
|---|---|
| ICD-9-CM | 01.32 |
Bilateral cingulotomy is a form of psychosurgery, introduced in 1948 as an alternative to lobotomy. Today, it is mainly used in the treatment of depression [1] and obsessive-compulsive disorder. In the early years of the twenty-first century, it was used in Russia to treat addiction. [2] [3] [4] It is also used in the treatment of chronic pain. [5] The objective of this procedure is the severing of the supracallosal fibres of the cingulum bundle, which pass through the anterior cingulate gyrus. [6]
Cingulotomy was introduced in the 1940s as an alternative to standard pre-frontal leucotomy/lobotomy in the hope of alleviating symptoms of mental illness whilst reducing the undesirable effects of the standard operation (personality changes, etc.). It was suggested by American physiologist John Farquhar Fulton who, at a meeting of the Society of British Neurosurgeons in 1947, said "were it feasible, cingulectomy in man would seem an appropriate place for limited leucotomy". This was derived from the hypothesis of James Papez who thought that the cingulum was a major component of an anatomic circuit believed to play a significant role in emotion. [7] The first reports of the use of cingulotomy on psychiatric patients came from J le Beau in Paris, Hugh Cairns in Oxford, and Kenneth Livingston in Oregon. [7]
Bilateral cingulotomy targets the anterior cingulate cortex, which is a part of the limbic system. This system is responsible for the integration of feelings and emotion in the human cortex. It consists of the cingulate gyrus, parahippocampal gyrus, amygdala, and the hippocampal formation. [8]
Studies in patients who were subject to bilateral cingulotomy, involving fMRI analyses, showed that the anterior cingulate cortex has a key role in cognitive control and is highly likely to be involved in the control of attentional response, whereas the dorsal part of that region of the brain was not identified to be involved in such a process, although this is still under dispute. [9] The function of the dorsal part of the cingulate cortex was connected to the sorting out and processing of conflicting information signals. In addition, neuroimaging studies also indicated that the anterior cingulate cortex participates in the modulation of cortical regions that are of higher order, as well as sensory processing areas. [10]
These findings have also been confirmed by stereotactic microelectrode analysis of single cortical neurons in a study, which involved nine patients undergoing bilateral cingulotomy. [9] The study investigated the effect of performing attention demanding tasks on the activity of 36 neurons located in the anterior cingulate cortex. Upon analyzing the results of the study, it was concluded that the anterior cingulate cortex is indeed involved in the modification of cognitive tasks that require attention, based on the fact that there was a change in the basal firing rate of neurons in that region during simulation of such tasks. [9]
Neuroimaging also uncovered different sub-regions in the anterior cingulate cortex itself, based on their function. These studies showed that the caudal part of the anterior cingulate cortex plays a more important function in cognitive activities that involve attention, salience, interference and response competition. [10] These results, combined with electrophysiological investigation of the function of neurons in the anterior cingulate cortex, have provided insights that can be used in the improvement of cingulotomy performed on patients treated for OCD. The basis behind this idea is the fact that a variation of certain tasks, Emotional Stroop tasks (ES), which have been particularly identified as exerting effects in OCD patients, activate neurons in the more rostral part of the anterior cingulate cortex. Thus, theoretically, if bilateral cingulotomy is performed in such a patient in the rostral anterior cingulate cortex, better results should be obtained. [9] [10]
Moreover, OCD has been associated with a malformation of the basal ganglia. [11] The function of this part of the human brain has been mapped to be composed of fiber tracks associated with numerous parallel cortico-striato-thalamocortical circuits (CSTC), which are involved in sensorimotor, motor, oculomotor as well as the cognitive processes that are manifested by the limbic system. [12] This pathway involves GABAergic inhibitory projections that serve as one of the means of communication between the different structures involved. [11] [12] It has been hypothesized that some forms of OCD are a result of disinhibition of one or several of the circuits that operate in the CSTC. [12] This is also indicated by a finding that showed a significant decrease in intracortical inhibition in OCD patients. [13] Thus, lesions in the anterior cingulate cortex might contribute to the lessening of the disinhibition effect. This hypothesis has been confirmed by another study, which assessed the cortical inhibitory and excitatory mechanisms in OCD. [13] The study measured the excitability of the motor cortex, as well as intracortical inhibition in OCD patients and a control group of healthy individuals. [13] The results showed a significant decrease in intracortical inhibition, which resulted in a slowdown of interstimulus intervals by 3 ms. [13] In addition to its proximity to and association with the limbic system and the amygdala in particular, which plays a key role in emotional experience, the anterior cingulate cortex shares afferent and efferent pathways with a number of thalamic nuclei as well as the posterior cingulate and part of some parietal, frontal and supplementary motor cortex. [14] All these underline the high likelihood that the anterior cingulate cortex must have some involvement in OCD.
Functional MRI analyses of the anterior cingulate cortex have also led to the introduction of bilateral cingulotomy for the treatment of chronic pain. Such application was introduced since the anterior cingulate cortex has been found to be related to the processing of nociceptive information input. In particular, the role of the anterior cingulate cortex is in the interpretation of how a stimulus affects a person rather than its actual physical intensity. [15] [16]
A book published in 1992 described how the operation was carried out at that time. In most cases the procedure started with the medical team taking a number of CT scan X-ray images of the brain of the patient. This step ensured that the exact target, the cingulate cortex, was mapped out, so that the surgeon could identify it. Burr holes were then created in the patient's skull using a drill. Lesions at the targeted tissue were made with the help of fine electrodes inserted at the right angle into the subject's brain based on plotting charts and making sure important arteries and blood vessels were intact. The electrode was placed in a probe, or a holder, with only its tip projecting. Upon the correct insertion of the holder into the brain tissue, air was injected and more scan images were taken. Then, after the medical team had made sure they were on the right track, the tip of the electrode was advanced to the plane of the cingulate where it was heated to 75-90 °C. Once the first lesion was created it served as a center around which several other lesions were created. In order to confirm whether lesions are made at the right place, scan images were taken postoperatively and analyzed. [17]
Recent technological advances, however, have made bilateral cingulotomy a more precise operation. For example, nowadays a neurosurgical team that performs the procedure can use an MRI to identify the location of the anterior and posterior commissures. This approach allows neurosurgeons to obtain a number of coronal images, which are then used to calculate the stereotactic coordinates of the target in the anterior cingulate cortex, where lesions need to be made. Moreover, the MRI enables more precise differentiation of the cell composition, and thus easily permits the identification of the grey matter in that region. This can then be further confirmed with the help of microelectrode recordings. [18]
Patients usually recover from this operation over a period of four days. However, there are cases of subjects being released from hospital after as few as 48 hours after the operation. The mild shorter postoperative complications that are most commonly related to bilateral cingulotomy are typical of head interventions and include but are not limited to nausea, vomiting, and headaches. However, in some cases, patients exhibit seizures that sometimes appear up to two months after the surgical intervention. It has been questioned whether this is relevant and can be attributed to cingulotomy because such seizures were observed in patients who already had a history of this condition. [19]
A 2002 study conducted at the Massachusetts General Hospital analyzed the outcome of bilateral cingulotomy in 44 patients for the treatment of OCD in the period between 1965 and 1986. Patients were followed up over a long term and evaluated based on several criteria: 1) how many of them were responders [lower-alpha 1] after a period of six months, 2) how many cingulotomies a patient had undergone before the examination of the effectiveness of the procedure, 3) whether the patient showed any significant change after the most recent procedure, and 4) what the side effects related to the procedure were. [19]
The follow-up of the patients produced contradictory results, which indicated that bilateral cingulotomy is not the optimal treatment for OCD. [19] Of the 44 patients, only 32% both fit the "responder" criteria and showed significant improvement compared to the other subjects. Another 14% exhibited some signs of improvement. Multiple cingulotomies correlated with a higher likelihood of continuing to respond to follow-up inquiries (6% more often fit the full "responder" criteria, 11% more often fit the partial "responder" criteria). However, the side effects associated with the procedure were numerous. Among the complaints that patients had after the surgery were apathy and deficits in memory, although these were rarely reported. In addition, some subjects complained of some form of urinary disturbance, ranging from urinary retention to incontinence. Hydrocephalus (2%) and seizures (2%) were also observed. [19]
Bilateral cingulotomy has also been used in the treatment of chronic refractory pain. A systematic review of 11 studies encompassing 224 patients found that anterior cingulotomy led to significant pain relief in greater than 60% of patients post-operatively as well as at one year following the procedure. [5] Of the included studies, one clinical study investigated the effect of bilateral cingulotomy for the treatment of refractory chronic pain. [20] In this case, 23 patients who were subject to 28 cingulotomies in total were followed up. The analyses aimed at determining how much the pain of each individual was affected after the procedure with the help of a questionnaire. In addition, the examiners tried to evaluate the impacts on social and family relations of the participants in the study. Based on the data obtained, cingulotomy for treatment of chronic pain showed promising results. 72% reported improvement in the level of pain experienced, and 50% indicated that they no longer required painkillers after cingulotomy. More than half of the patients also claimed that the surgical procedure was beneficial and contributed to the improvement of their social interactions. [20]
Psychosurgery, also called neurosurgery for mental disorder (NMD), is the neurosurgical treatment of mental disorder. Psychosurgery has always been a controversial medical field. The modern history of psychosurgery begins in the 1880s under the Swiss psychiatrist Gottlieb Burckhardt. The first significant foray into psychosurgery in the 20th century was conducted by the Portuguese neurologist Egas Moniz who during the mid-1930s developed the operation known as leucotomy. The practice was enthusiastically taken up in the United States by the neuropsychiatrist Walter Freeman and the neurosurgeon James W. Watts who devised what became the standard prefrontal procedure and named their operative technique lobotomy, although the operation was called leucotomy in the United Kingdom. In spite of the award of the Nobel prize to Moniz in 1949, the use of psychosurgery declined during the 1950s. By the 1970s the standard Freeman-Watts type of operation was very rare, but other forms of psychosurgery, although used on a much smaller scale, survived. Some countries have abandoned psychosurgery altogether; in others, for example the US and the UK, it is only used in a few centres on small numbers of people with depression or obsessive-compulsive disorder (OCD). In some countries it is also used in the treatment of schizophrenia and other disorders.
Deep brain stimulation (DBS) is a surgical procedure that implants a neurostimulator and electrodes which sends electrical impulses to specified targets in the brain responsible for movement control. The treatment is designed for a range of movement disorders such as Parkinson's disease, essential tremor, and dystonia, as well as for certain neuropsychiatric conditions like obsessive-compulsive disorder (OCD) and epilepsy. The exact mechanisms of DBS are complex and not entirely clear, but it is known to modify brain activity in a structured way.
The cingulate cortex is a part of the brain situated in the medial aspect of the cerebral cortex. The cingulate cortex includes the entire cingulate gyrus, which lies immediately above the corpus callosum, and the continuation of this in the cingulate sulcus. The cingulate cortex is usually considered part of the limbic lobe.
In the human brain, the anterior cingulate cortex (ACC) is the frontal part of the cingulate cortex that resembles a "collar" surrounding the frontal part of the corpus callosum. It consists of Brodmann areas 24, 32, and 33.
The caudate nucleus is one of the structures that make up the corpus striatum, which is a component of the basal ganglia in the human brain. While the caudate nucleus has long been associated with motor processes due to its role in Parkinson's disease, it plays important roles in various other nonmotor functions as well, including procedural learning, associative learning and inhibitory control of action, among other functions. The caudate is also one of the brain structures which compose the reward system and functions as part of the cortico–basal ganglia–thalamic loop.
The frontal lobe is the largest of the four major lobes of the brain in mammals, and is located at the front of each cerebral hemisphere. It is parted from the parietal lobe by a groove between tissues called the central sulcus and from the temporal lobe by a deeper groove called the lateral sulcus. The most anterior rounded part of the frontal lobe is known as the frontal pole, one of the three poles of the cerebrum.
Polymicrogyria (PMG) is a condition that affects the development of the human brain by multiple small gyri (microgyri) creating excessive folding of the brain leading to an abnormally thick cortex. This abnormality can affect either one region of the brain or multiple regions.
The insular cortex is a portion of the cerebral cortex folded deep within the lateral sulcus within each hemisphere of the mammalian brain.
In neuroanatomy, the cingulum is a nerve tract – a collection of axons – projecting from the cingulate gyrus to the entorhinal cortex in the brain, allowing for communication between components of the limbic system. It forms the white matter core of the cingulate gyrus, following it from the subcallosal gyrus of the frontal lobe beneath the rostrum of corpus callosum to the parahippocampal gyrus and uncus of the temporal lobe.
The posterior cingulate cortex (PCC) is the caudal part of the cingulate cortex, located posterior to the anterior cingulate cortex. This is the upper part of the "limbic lobe". The cingulate cortex is made up of an area around the midline of the brain. Surrounding areas include the retrosplenial cortex and the precuneus.
Cerebral achromatopsia is a type of color blindness caused by damage to the cerebral cortex of the brain, rather than abnormalities in the cells of the eye's retina. It is often confused with congenital achromatopsia but underlying physiological deficits of the disorders are completely distinct. A similar, but distinct, deficit called color agnosia exists in which a person has intact color perception but has deficits in color recognition, such as knowing which color they are looking at.
Foix–Chavany–Marie Syndrome (FCMS), also known as bilateral opercular syndrome, is a neuropathological disorder characterized by paralysis of the facial, tongue, pharynx, and masticatory muscles of the mouth that aid in chewing. The disorder is primarily caused by thrombotic and embolic strokes, which cause a deficiency of oxygen in the brain. As a result, bilateral lesions may form in the junctions between the frontal lobe and temporal lobe, the parietal lobe and cortical lobe, or the subcortical region of the brain. FCMS may also arise from defects existing at birth that may be inherited or nonhereditary. Symptoms of FCMS can be present in a person of any age and it is diagnosed using automatic-voluntary dissociation assessment, psycholinguistic testing, neuropsychological testing, and brain scanning. Treatment for FCMS depends on the onset, as well as on the severity of symptoms, and it involves a multidisciplinary approach.
Ablative brain surgery is the surgical ablation by various methods of brain tissue to treat neurological or psychological disorders. The word "Ablation" stems from the Latin word Ablatus meaning "carried away". In most cases, however, ablative brain surgery does not involve removing brain tissue, but rather destroying tissue and leaving it in place. The lesions it causes are irreversible. There are some target nuclei for ablative surgery and deep brain stimulation. Those nuclei are the motor thalamus, the globus pallidus, and the subthalamic nucleus.
Auditory agnosia is a form of agnosia that manifests itself primarily in the inability to recognize or differentiate between sounds. It is not a defect of the ear or "hearing", but rather a neurological inability of the brain to process sound meaning. While auditory agnosia impairs the understanding of sounds, other abilities such as reading, writing, and speaking are not hindered. It is caused by bilateral damage to the anterior superior temporal gyrus, which is part of the auditory pathway responsible for sound recognition, the auditory "what" pathway.
The biology of obsessive–compulsive disorder (OCD) refers biologically based theories about the mechanism of OCD. Cognitive models generally fall into the category of executive dysfunction or modulatory control. Neuroanatomically, functional and structural neuroimaging studies implicate the prefrontal cortex (PFC), basal ganglia (BG), insula, and posterior cingulate cortex (PCC). Genetic and neurochemical studies implicate glutamate and monoamine neurotransmitters, especially serotonin and dopamine.
Cortical stimulation mapping (CSM) is a type of electrocorticography that involves a physically invasive procedure and aims to localize the function of specific brain regions through direct electrical stimulation of the cerebral cortex. It remains one of the earliest methods of analyzing the brain and has allowed researchers to study the relationship between cortical structure and systemic function. Cortical stimulation mapping is used for a number of clinical and therapeutic applications, and remains the preferred method for the pre-surgical mapping of the motor cortex and language areas to prevent unnecessary functional damage. There are also some clinical applications for cortical stimulation mapping, such as the treatment of epilepsy.
Ulegyria is a diagnosis used to describe a specific type of cortical scarring in the deep regions of the sulcus that leads to distortion of the gyri. Ulegyria is identified by its characteristic "mushroom-shaped" gyri, in which scarring causes shrinkage and atrophy in the deep sulcal regions while the surface gyri are spared. This condition is most often caused by hypoxic-ischemic brain injury in the perinatal period. The effects of ulegyria can range in severity, although it is most commonly associated with cerebral palsy, mental retardation and epilepsy. N.C. Bresler was the first to view ulegyria in 1899 and described this abnormal morphology in the brain as “mushroom-gyri." Although ulegyria was first identified in 1899, there is still limited information known or reported about the condition.
Psychosurgery, also called neurosurgery for mental disorder or functional neurosurgery, is surgery in which brain tissue is destroyed with the aim of alleviating the symptoms of mental disorder. It was first used in modern times by Gottlieb Burckhardt in 1891, but only in a few isolated instances, not becoming more widely used until the 1930s following the work of Portuguese neurologist António Egas Moniz. The 1940s was the decade when psychosurgery was most popular, largely due to the efforts of American neurologist Walter Freeman; its use has been declining since then. Freeman's particular form of psychosurgery, the lobotomy, was last used in the 1970s, but other forms of psychosurgery, such as the cingulotomy and capsulotomy have survived.
The delayed-maturation theory of obsessive–compulsive disorder suggests that obsessive–compulsive disorder (OCD) can be caused by delayed maturation of the frontal striatal circuitry or parts of the brain that make up the frontal cortex, striatum, or integrating circuits. Some researchers suspect that variations in the volume of specific brain structures can be observed in children that have OCD. It has not been determined if delayed-maturation of this frontal circuitry contributes to the development of OCD or if OCD is the ailment that inhibits normal growth of structures in the frontal striatal, frontal cortex, or striatum. However, the use of neuroimaging has equipped researchers with evidence of some brain structures that are consistently less adequate and less matured in patients diagnosed with OCD in comparison to brains without OCD. More specifically, structures such as the caudate nucleus, volumes of gray matter, white matter, and the cingulate have been identified as being less developed in people with OCD in comparison to individuals that do not have OCD. However, the cortex volume of the operculum (brain) is larger and OCD patients are also reported to have larger temporal lobe volumes; which has been identified in some women patients with OCD. Further research is needed to determine the effect of these structural size differences on the onset and degree of OCD and the maturation of specific brain structures.
Meditation and pain is the study of the physiological mechanisms underlying meditation-specifically its neural components- that implicate it in the reduction of pain perception.
