Abulia following penetrating brain injury during endoscopic sinus surgery with disruption of the anterior cingulate circuit: case report

Severe Cerebral Complications Secondary to Perforation Injury of the Anterior Skull Base During Sinonasal Surgery: An Underappreciated Problem?

OBJECTIVE

Functional endonasal sinus surgery (FESS) is widely practiced and is considered a generally safe procedure. Skull base injuries occur in <1% of procedures and are typically associated with cerebrospinal fluid leaks. Rarely, skull base injuries might result in cerebral lesions. Here we present a series of 4 patients with iatrogenic perforating injuries of the anterior skull base and cerebral lesions after routine FESS.

METHODS

Four patients with iatrogenic perforating cerebral lesions after routine FESS, performed at other institutions, were referred to a tertiary neurosurgery department. Within a 10-year period these procedures were performed in 3 patients as endoscopic FESS and as a microscopic FESS in 1 patient.

RESULTS

There were 3 men and 1 woman. Mean age at the time of surgery was 50 years. In 3 instances (in which an endoscope was used), the ear, nose, and throat physician had noted perforation of the skull base during surgery, but it went unnoticed in 1 patient operated with the microscope. Frontal lobe hematoma occurred in all patients, and in 3 of them cerebral infarction developed secondary to injury of branches of the anterior cerebral artery. Three patients developed acute hydrocephalus. Two had rapid global brain swelling and they succumbed within days. The other 2 patients survived without apparent neurological deficits.

CONCLUSIONS

Cerebral lesions during FESS still occur in contemporary surgery and they are possibly underreported. Even with prompt conservative and surgical measures, these lesions may result in catastrophic outcome. Associated vascular injuries have a worse prognosis. The only risk factor associated with lethal outcome in our series was younger age.

Differential relationships between apathy and depression with white matter microstructural changes and functional outcomes

Small vessel disease is a stroke subtype characterized by pathology of the small perforating arteries, which supply the sub-cortical structures of the brain. Small vessel disease is associated with high rates of apathy and depression, thought to be caused by a disruption of white matter cortical-subcortical pathways important for emotion regulation. It provides an important biological model to investigate mechanisms underlying these key neuropsychiatric disorders. This study investigated whether apathy and depression can be distinguished in small vessel disease both in terms of their relative relationship with white matter microstructure, and secondly whether they can independently predict functional outcomes. Participants with small vessel disease (n = 118; mean age = 68.9 years; 65% male) defined as a clinical and magnetic resonance imaging confirmed lacunar stroke with radiological leukoaraiosis were recruited and completed cognitive testing, measures of apathy, depression, quality of life and diffusion tensor imaging. Healthy controls (n = 398; mean age = 64.3 years; 52% male) were also studied in order to interpret the degree of apathy and depression found within the small vessel disease group. Firstly, a multilevel structural equation modelling approach was used to identify: (i) the relationships between median fractional anisotropy and apathy, depression and cognitive impairment; and (ii) if apathy and depression make independent contributions to quality of life in patients with small vessel disease. Secondly, we applied a whole-brain voxel-based analysis to investigate which regions of white matter were associated with apathy and depression, controlling for age, gender and cognitive functioning. Structural equation modelling results indicated both apathy (r = -0.23, P ≤ 0.001) and depression (r = -0.41, P ≤ 0.001) were independent predictors of quality of life. A reduced median fractional anisotropy was significantly associated with apathy (r = -0.38, P ≤ 0.001), but not depression (r = -0.16, P = 0.09). On voxel-based analysis, apathy was associated with widespread reduction in white matter integrity, with the strongest effects in limbic association tracts such as the anterior cingulum, fornix and uncinate fasciculus. In contrast, when controlling for apathy, we found no significant relationship between our white matter parameters and symptoms of depression. In conclusion, white matter microstructural changes in small vessel disease are associated with apathy but not directly with depressive symptoms. These results suggest that apathy, but not depression, in small vessel disease is related to damage to cortical-subcortical networks associated with emotion regulation, reward and goal-directed behaviour.

Apathy is associated with white matter abnormalities in anterior, medial brain regions in persons with HIV infection

Apathy is a relatively common psychiatric syndrome in HIV infection, but little is known about its neural correlates. In the present study, we examined the associations between apathy and diffusion tensor imaging (DTI) indices in key frontal white matter regions in the thalamocorticostriatal circuit, which has been implicated in the expression of apathy. Nineteen participants with HIV infection and 19 demographically comparable seronegative comparison subjects completed the Apathy subscale of the Frontal Systems Behavioral Scale as a part of a comprehensive neuropsychiatric research evaluation. When compared to the seronegative participants, the HIV+ group had significantly more frontal white matter abnormalities. Within HIV+ persons, and as predicted, higher ratings of apathy were associated with greater white matter alterations in the anterior corona radiata, genu, and orbital medial prefrontal cortex. The associations between white matter alterations and apathy were independent of depression and were stronger among participants with lower current cluster of differentiation 4 (CD4) counts. All told, these findings indicate that apathy is independently associated with white matter abnormalities in anterior, medial brain regions in persons infected with HIV, particularly in the setting of lower current immune functioning, which may have implications for antiretroviral therapy.

Neurocognitive mechanisms of perception-action coordination: a review and theoretical integration

The present analysis aims at a theoretical integration of, and a systems-neuroscience perspective on, a variety of historical and contemporary views on perception-action coordination (PAC). We set out to determine the common principles or lawful linkages between sensory and motor systems that explain how perception is action-oriented and how action is perceptually guided. To this end, we analyze the key ingredients to such an integrated framework, examine the architecture of dual-system conjectures of PAC, and endeavor in an historical analysis of the key characteristics, mechanisms, and phenomena of PACs. This analysis will reveal that dual-systems views are in need of fundamental re-thinking, and its elements will be amalgamated with current views on action-oriented predictive processing into a novel integrative theoretical framework (IMPPACT: Impetus, Motivation, and Prediction in Perception-Action Coordination theory). From this framework and its neurocognitive architecture we derive a number of non-trivial predictions regarding conative, motive-driven PAC. We end by presenting a brief outlook on how IMPPACT might present novel insights into certain pathologies and into action expertise.

Dysexecutive behaviour following deep brain lesions--a different type of disconnection syndrome?

The suppression of automatic prepotent behaviour in favour of more successful, more 'appropriate' behaviour is the primary function of the frontal lobe. Five frontal-subcortical circuits connect the frontal lobe to the basal ganglia and the thalamus. We report 17 patients with small lesions in the downstream structures of the frontal-subcortical circuits displaying severe dysexecutive behaviour. Positron emission tomography (PET) demonstrated hypometabolism of the frontal lobe in some of these patients. The literature on frontal lobe dysfunction after lesions in the basal ganglia and thalamus is discussed and the semiology of frontal lobe dysfunction in relation to the frontal-subcortical circuits is highlighted. Derived from our findings we suggest a disconnection syndrome of the frontal lobe caused by lesions in the downstream structures of the frontal-subcortical circuits.

The trajectory of apathy after deep brain stimulation: from pre-surgery to 6 months post-surgery in Parkinson's disease

Deep brain stimulation (DBS) has been associated with increased apathy in patients with PD, yet studies lack longitudinal data and have not assessed differences between sites of implantation (i.e. STN versus GPi). We assessed apathy prior to surgery and 6 months post-surgery using a longitudinal design-latent growth curve modeling. We hypothesized that apathy would increase post-surgery, and be related to subthalamic nucleus (versus globus pallidus interna) implantation. Forty-eight PD patients underwent unilateral surgery to either GPi or STN and completed the Apathy Scale prior to surgery and 2, 4, and 6 months post-surgery. Forty-eight matched PD controls completed the Apathy Scale at a 6-month interval. Results indicated apathy increased linearly from pre- to 6-months post-DBS by .66 points bi-monthly, while apathy in the control group did not change. There was no relationship between apathy and DBS site. Higher baseline depression was associated with higher baseline apathy, but not with change in apathy. Middle-aged adults (<65) had a steeper trajectory of apathy than older adults (≥ 65). Apathy trajectory was not related to motor severity, laterality of DBS, levodopa medication reduction, or motor changes after surgery.

Neuro-ophthalmic complications of endoscopic sinus surgery

PURPOSE OF REVIEW

This review aims to provide an overview of powered endoscopic sinus surgery and raise awareness of the possible neuro-ophthalmic complications associated with the procedure.

RECENT FINDINGS

The neuro-ophthalmic complications of endoscopic sinus surgery can be categorized into five anatomic sites: eye, orbit, optic nerve, extraocular muscle, and lacrimal drainage system. Double vision may be caused by various ocular motility abnormalities. Visual loss may be the result of orbital hemorrhage or direct optic nerve trauma.

SUMMARY

A wide range of neuro-ophthalmic complications may occur during endoscopic sinus surgery. The use of powered cutting instruments has been a recent advance in endoscopic sinus surgery, but it has also been implicated in rapid, irreversible, and devasting complications. Multiple preoperative and intraoperative factors appear to be involved in the adverse events associated with endoscopic sinus surgery. Ophthalmologists may be asked to evaluate and manage ocular damage in patients who have undergone endoscopic sinus surgery, and in some cases emergent intervention may be required in an attempt to avoid permanent visual loss.