Prognosis of chronic subdural hematomas

This article considers factors that may be of prognostic value in evaluating the chronic subdural hematoma (CSH) patient. It also examines conditions that predispose the development of a CSH. Variables such as admission neurologic status and presenting symptomatology are reviewed. Radiologic parameters (i.e., CSH density and midline shift) and intraoperative findings (i.e., pressure and pulse) are discussed.     

Spontaneous resolution of chronic subdural hematomas

Four patients with chronic subdural hematomas, all of which resolved spontaneously, were followed from the time of injury to resolution of the chronic subdural hematoma. Periodic computed tomographic (CT) scans showed spontaneous resolution 78, 174, 231, and 326 days after the development of the chronic subdural hematoma, respectively. Features of the CT scans and a possible mechanism of spontaneous resolution are discussed.     

Eosinophil degranulation in the capsule of chronic subdural hematomas

A previously unrecognized role of eosinophils in chronic subdural hematomas is described. Outer membranes of hematomas with marked infiltration by eosinophils were studied ultrastructurally with particular attention to the degranulation of these cells. In all of the five cases studied, degranulation was observed. Disintegration of the cells contributed to the release of granules. The free granules, the matrix of which has been demonstrated to contain plasminogen, were often circulating in the vascular lumen and trapped among the aggregated platelets. They were also found within the fragile vascular wall surrounded by fibrinoid material and in the edematous perivascular interstitium. Some of the perivascular eosinophils showed frank solubilization of granule matrix contents in spite of unaltered crystalloids. These findings suggest a role of eosinophils in the development of local hyperfibrinolysis within the outer membranes, which might contribute to the fluidity of chronic subdural hematomas and the resultant leakage of blood from the vessels in the capsules.     

Magnetic resonance images of chronic subdural hematomas

Magnetic resonance imaging (MRI) and computerized tomography (CT) scans of 18 patients with 20 chronic subdural hematomas were compared. In many ways, MRI was superior to CT for demonstrating the hematomas. In general, chronic subdural hematomas were hyperintense on both T1- and T2-weighted MRI. The T1 values of chronic subdural hematomas were significantly shorter than gray matter values and significantly longer than white matter values. The T2 values were significantly longer than both gray matter and white matter values. These findings were consistent with previous reports. However, six hematomas (30%) were iso- or hypointense on T1-weighted images. Possible mechanisms responsible for the difference in intensity of chronic subdural hematoma on MRI are discussed, and the important role of methemoglobin formation is emphasized.     

Significance of eosinophilic granulocytes in chronic subdural hematomas

Despite a number of studies on infiltration of eosinophilic granulocytes into the outer membrane of chronic subdural hematomas, the significance of this phenomenon is not clear. We investigated histologically the membranes of 40 patients with chronic subdural encapsulated hematoma. Infiltrations with eosinophilic leucocytes were found in the granulation tissue of the inner layer of the outer membrane, either diffuse and sporadic (12 cases) or as massive agglomerations (28 cases). Fifty percent of the patients with marked infiltrations were between 61 and 80 years old. In 5 cases Charcot-Leyden crystals were identified. The numerous functions of the eosinophils play a more important role in repair than in maintenance of fluidity of hematomas.     

Computed tomographic characteristics of chronic subdural hematomas

Although medical history and physical examination should lead to diagnosis of chronic subdural hematomas, 40% of these patients are likely to be misdiagnosed because many of these symptoms occur in other disease processes, such as transient ischemic attacks, stroke, dementia, and tumors. Computed tomography remains one of the most useful tools in the evaluation of these patients because of its rapidity, cost, availability, and pathologic sensitivity.     

A brief history of chronic subdural hematomas

Examination of human remains tells us that subdural hematomas have been with mankind for thousands of years. Their recognition as distinct clinical entities is considerably more recent, and it has only been in the last century that the cause of chronic subdural hematomas has been adequately elucidated. The history of this discovery process is interesting and sheds light on the nature of scientific progress in general.     

The role of exudation in chronic subdural hematomas

OBJECT: Chronic subdural hematomas (SDHs) are a local inflammatory process that causes the formation of a granulation tissue often referred to as the external or outer membrane. This membrane has abnormally permeable macrocapillaries. Therefore, exudation from the macrocapillaries in the outer membrane of chronic SDH may play an important role in the enlargement of chronic SDH. In this study the authors investigated the role of exudation in chronic SDH. METHODS: The authors examined 24 patients (16 men and eight women; age range 38-86 years [mean age 61.4 years]) with 27 chronic SDHs. The clinical status of the patients was evaluated according to the classification described by Markwalder. The diagnosis was established on computed tomography (CT) scans in all cases. The authors also used the Nomura Classification for judging the lesion's appearance on CT scans. Immediately after the diagnosis, all patients were administered 20 mCi (740 mBq) technetium-99m human serum albumin. Four hours later, blood and SDH samples were taken and radioactivity levels were measured in each. The ratio of activity of the samples taken from chronic SDH to the radioactivity of blood was determined as a percentage and defined as the exudation rate. On the follow-up CT scan obtained on postoperative Day 20, subdural collections thicker than 5 mm were determined to be a reaccumulation. RESULTS: The correlations between the exudation rate and age of the patients, clinical grades, CT appearances, and amount of reaccumulation were investigated. In this series the average exudation rate was 13.24% (range 2.05-28.88%). The mean exudation rates according to the clinical grades assigned to patients were as follows: Grade 0, 8.67 +/- 5.64% (three patients); Grade 1, 5.07 +/- 1.43% (eight patients); Grade 2, 17.87 +/- 3.73% (seven patients); and Grade 3, 19.65 +/- 7.67% (six patients). Exudation rates in patients with Grades 2 and 3 were significantly higher than those in Grades 0 and 1 (p < 0.05). The mean exudation rates according to the lesion's appearance on CT scans were found as follows: hypodense appearance, 6.55 +/- 4.52% (eight patients); isodense appearance, 11.07 +/- 6.32% (five patients); hyperdense appearance, 19.47 +/- 13.61% (three patients); and mixed-density appearance, 17.40 +/- 5.80% (nine patients). The differences among the groups were significant (p < 0.05). The average exudation rate was statistically higher in the patients with reaccumulation (16.30 +/- 8.16%) than that in the patients without reaccumulation (9.96 +/- 6.84%) (p < 0.05). CONCLUSIONS: The exudation rate in chronic SDH is correlated with a higher clinical grade (Markwalder Grade 2 or 3), mixed-density CT appearance, and reaccumulation. Therefore, exudation from macrocapillaries in the outer membrane of chronic SDH probably plays an important role in the pathophysiology and the growth of chronic SDH.     

Reversible dementia in patients with chronic subdural hematomas

OBJECT: Neuropsychiatric changes following surgery for chronic subdural hematomas (CSDHs) were analyzed in 26 patients (21 men and five women) by using the Mini-Mental State Examination (MMSE) and the Hasegawa Dementia Scale-Revised (HDS-R) to determine factors that potentially contribute to neuropsychiatric recovery. METHODS: Burr hole irrigation was performed in every patient to treat the CSDH. The patients' profiles, including age and sex, neuroimaging findings (such as hematoma volume and thickness, as well as midline shift), and preoperative and postoperative scores on the MMSE, HDS-R, and activities of daily living (ADL) scale were recorded. According to preoperative MMSE scores, eight patients (30.8%) were classified as mentally healthy and 18 (69.2%) as suffering from dementia before surgery. Nine of the 18 patients with dementia recovered to a normal psychological state following surgery. Surgery improved not only the patients' independence in ADL (p = 0.0026), but also their neuropsychiatric functions such as orientation and calculation, as estimated by scores on the MMSE (p = 0.0002) and the HDS-R (p = 0.0008). Factors affecting neuropsychiatric status on admission were midline shift (p = 0.0398) and ADL score (p = 0.0124); factors that could be used to predict neuropsychiatric recovery after surgery were patient age (p = 0.0027) and ADL score (p = 0.0193). The results of a logistic regression analysis demonstrated that significant predictors of neuropsychiatric recovery after surgery include the following: patient age (p = 0.0049, odds ratio [OR] = 0.842) and preoperative ADL (p = 0.0056, OR = 0.471), MMSE (p < 0.0001, OR = 1.895), and HDS-R (p = 0.0073, OR = 1.303) scores. Results of subgroup analyses demonstrated that patients younger than 74 years of age and those who had preoperative scores lower than 5 on the converted ADL scale, higher than 10 on the MMSE, or higher than 9 on the HDS-R on admission were found to have a significantly better recovery of neuropsychiatric functions after surgery. CONCLUSIONS: Dementia is reversible in many patients with CSDH, and surgery can improve not only independence in ADL, but also neuropsychiatric functions. Patients who are younger and/or those who have lower preoperative ADL scores and/or higher preoperative MMSE or HDS-R scores will achieve a good recovery with regard to neuropsychiatric functions after surgery. Estimations of neuropsychiatric function based on MMSE and HDS-R scores were found to be useful in predicting functional outcomes in patients with CSDH.     

Ossified chronic subdural hematoma: case report

A case of ossified chronic subdural hematoma is presented in a 13-year-old male in whom the mass was surgically removed. His neurological deficits continued afterward but were less severe.     

Factors responsible for prognosis of chronic subdural hematomas

239 adult patients with chronic subdural hematoma were reviewed in order to analyse recent characteristics, and the responsible factors affecting functional prognosis. Patients with hygroma, diagnosed by the nature of the subdural fluid, were included since the mode of treatment is regarded as the same. 226 cases were surgically treated with standardized two burr-holes and irrigation, within which 24 cases required reoperation and 13 cases were medically treated since the hematoma was small and there was no mass effect. Functional outcome was evaluated by the Glasgow Outcome Scale. The number of cases have gradually increased, especially among elderly patients and in female ones. 179 patients were categorised as having good recovery, 25 as moderately disabled, 27 as severely disabled, 3 as persistently vegetative, and 5 patients died. Aged patients with preoperative mental change and a disturbance of consciousness, with low dense or mixed dense hematoma without sizable mass effect, with watery-clear or xanthochromic fluid cavity tended to have poorer outcome. Also the prognosis of patients not operated on was poor despite the spontaneous disappearance of the cavity. The delay in re-expansion of the brain had less bearing on the functional prognosis than might be expected. The factors which impeded good recovery were primary brain damage due to preceding diseases such as cerebral infarct or hemorrhage, initial head injury, parkinsonism, and postoperative psychiatric disturbances. The mean age of these patients was significantly higher than those with good recovery.(ABSTRACT TRUNCATED AT 250 WORDS)     

Surgical treatment of chronic subdural hematomas in infants.

Subdural hematomas in infants are associated with a high risk of recurrence. In an effort to combat this risk, a surgical procedure consisting of excision of the subdural membranes, a reduction of the craniocerebral disproportion and a restoration of the normal angle of junction of the cerebral bridging veins and the superior sagittal sinus is proposed.     

Peritoneal drainage of chronic subdural hematomas in older patients

Most patients with chronic subdural hematoma are successfully treated with trephination and external drainage. However, hematomas with thick membranes may persist or recur, needing reoperation or major surgery such as craniotomy with membranectomy. In 14 patients aged over 60 years, internal peritoneal drainage of the hematoma by a low-pressure shunt system proved to be a reliable method of treatment with the following advantages: rapid neurological improvement; immediate mobilization; little stress for the patient; no recurrence; disappearance of the membranes; and slow and well-tolerated cerebral reexpansion without hypotension. Successful use of this method has been reported previously in children, but not in adults.