Description of posterior fossa syndrome in children after posterior fossa brain tumor surgery

Description of Posterior Fossa Syndrome in Children After Posterior Fossa Brain Tumor Surgery Elizabeth A. Kirk, RN, MSN, CNRN, Vanessa C. Howard, RN, MSN, CPON, and Cheryl A. Scott, RN, BSN, MPA Brain tumors are the second most common malignancy in children less than 15 years of age and the most common solid tumor of childhood. Approximateiy 60% to 70% of pediatric brain tumors originate in the posterior fossa. Since 1989, the two hospitals that comprise the setting for this study have treated 121 children with posterior fossa brain tumors. A postoperative syndrome, labeled posterior fossa syndrome, has been identified in certain children. This syndrome involves a variety of signs and symptoms including mutism or speech disturbances, dysphagia, decreased motor movement, cranial nerve palsies and, emotional lability. These signs and symptoms develop from an average range of 24 to 107 hours after surgery and may take weeks to months to resolve. The exact etiology of the syndrome is unknown. The purpose of this retrospective medical records review of 19 children diagnosed with posterior fossa syndrome is to describe the symptoms of the syndrome. Early recognition of this syndrome could facilitate preventive and restorative patient care, prevent subsequent complications, decrease length of hospital stays, and promote patient and family understanding of and coping with the syndrome. 0 1995 by Association of Pediatric Oncology Nurses.

T

HERE IS VARIED and rather limited information in the literature regarding the occurrence rates of central nervous system (CNS) tumors in children. Primary CNS neoplasms are the second most frequent malignancy in children younger than 15 years of age (exceeded only by leukemia). The estimated annual occurrence rate is 2.2 to 2.5 new cases per 100,000 children or more than 1,200 new CNS neoplasm cases yearly.‘,* Posterior fossa brain tumors account for approximately 60% to 70% of all pediatric brain

From the Neurosciences Patient Care Unit, Le Bonheur Children’s Medical Center and St. Jude Children’s Research Hospital, Memphis, TN. Address reprint requests to Vanessa C. Howard, RN, MSN, CPON, 332 N. Lauderdale, PO Box 318, Memphis, TN 38101. 0 1995 by Association of Pediatric Oncology Nurses 1043-4542/95/1204-0002$3.00/0

Journal

of Pediatric

Oncology

Nursing,

tumors.3 The most common types of brain tumors in the posterior fossa are medulloblastoma, cerebellar astrocytoma, brain stem glioma (excluded in some series), and ependymoma.3,4 Forty percent to 50% of the posterior fossa tumors are medulloblastoma, also called primitive neuroectodermal tumor (PNET).‘v’,~ The relative incidence of cerebellar astrocytomas varies from 10% to 40% and ependymomas vary from 5% to 20% .‘,* These wide ranges of variances are unexplained in the references. In our posterior fossa brain tumor series, dating back to 1989, medulloblastoma accounts for approximately 55% (or 67 of 121 patients), pilocytic and anaplastic astrocytoma, 30% (36 patients), ependymoma, 13% (16 patients), oligodendroglioma, 1% , and glioblastoma multiforme for 1% of all treated patients. According to Heideman et al,’ in medulloblastoma the peak age of occurrence is 5 years of age. Typically, ependymomas are tumors of the Vol 12, No 4 (October),

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very young child, with more than 50% occurring in children younger than 5 years of age.ls5 Cerebellar astrocytomas can occur throughout the first decade of life with the average age at occurrence being 6.5 to 9 years of age.1,6*7 The child with a posterior fossa brain tumor typically presents with variable signs and symptoms. The most common signs and symptoms are headache, vomiting (particularly in the morning), and ataxia. The clinical presentation may also include a myriad of signs and symptoms from increased intracranial pressure (IICP), obstructive hydrocephalus, to disease progression/extension. Diplopia (cranial nerve VI) and other cranial nerve findings, papilledema, meningismus, hyporeflexia or hyperreflexia, lethargy, irritability, personality change, decreased school performance, or loss of developmental milestones may also be present.lz2 Treatment of pediatric posterior fossa brain tumors encompasses several modalities, including surgery, chemotherapy, and radiation therapy. The combination of effective treatment protocols and improved surgical technology, including an aggressive surgical approach for a gross total surgical removal, has significantly improved the survival of children with posterior fossa brain tumors.* The prognosis for children with posterior fossa tumors is related to tumor histology, staging, neuroaxis dissemination, location, patient’s age, and extent of surgical resection. For example, medulloblastoma patients with disease extending beyond the posterior fossa have a reported 36% progression-free survival at 5 years compared with 59% for patients without extension of their disease.g Although the morbidity associated with CNS tumors in childhood has not been quantified, experience suggests that the morbidity is significant and affects both motor and cognitive development. Mulhern et al” studied the neurodevelopmental status of 14 infants and young children treated with preirradiation chemotherapy for malignant brain tumors. Most of the children exhibited below normal performance status and mental abilities before receiving chemotherapy and after completion. After radiation therapy, declining functional status was also common. Six of the 12 surviving children had residual visual impairment. Motor deficits were noted in nine of the surviving patients,

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and two children with posterior fossa brain tumors had mild to moderate ataxia. As previously described, research has discovered premorbid neurological deficits associated with the tumor itself. Clinical practice reinforces these findings and shows morbidity associated with the various types of treatments as well.’

Posterior Fossa Syndrome There is limited literature available on the unique, delayed neurological changes after posterior fossa tumor resection. Most reports focus on pseudobulbar palsy or mutism.“-I7 Wisoff and Epstein” reported seven cases of delayed onset of supranuclear cranial nerve palsies associated with emotional lability that resolved in several weeks to months. They noted that transient or occasionally permanent nuclear and infranuclear palsies are well-known complications attributed to posterior fossa surgery in children. These deficits are usually present immediately after surgery. Rekate et alI2 reported six cases of children with mutism after posterior fossa brain tumor surgery. This mutism persisted for 1 to 3 months. In 1990, Ferrante et alI5 reviewed the medical records of 18 children, ages 2 to 11 years, who developed mutism 18 to 72 hours after posterior fossa surgery. The disorder lasted an average of 7.9 weeks. The exact cause of posterior fossa syndrome has not been identified. Several possible causes discussed in the literature include (1) cerebellar insult, (2) hydrocephalus, (3) surgical resection of a large midline posterior fossa tumor, (4) meningeal spread of tumor, (5) cerebellar atrophy, and (6) vascular disturbances.’ ‘-I7

Study Purpose The purposes of this descriptive, retrospective study were (1) to identify the symptoms of posterior fossa syndrome, (2) to assess the time of onset of the signs and symptoms, and (3) to assess degree of resection, pathology, postoperative intracranial monitoring and shunting, when applicable. The resulting findings were then used as a basis for specifying appropriate nursing interventions before and during syndrome occurrence.

Posterior Fossa

Methodology

Syndrome

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medical center. Degree of surgical resections was classified as subtotal, near total, and gross total (Table 1). The median length of hospital stay, postoperatively, was 12 days (range, 6 to 21 days).

Design

A descriptive design lends itself to observing, describing, and documenting phenomena as they naturally OCCU~.~~This study used a descriptive design to determine postoperative symptoms of a group of patients who had undergone surgery for resection of a posterior fossa brain tumor.

Data Collection Procedure and Instrumentation

The study was conducted using a retrospective medical record review of 19 patients who had experienced the symptoms associated with posterior fossa syndrome. A data collection tool was developed because of the lack of an existent one. The tool was developed using the symptoms associated with the syndrome that had been primarily observed in these investigators’ clinical practice and from previous reports in the literature.“-I8 Initially, the tool was developed by two nurses and a pediatric neurologist and included only eight symptoms and five time points. The tool was tested by two of the investigators by reviewing two medical records. After a more thorough literature review and discussion of the symptoms, time points, and previous testing by the two investigators, a new tool was developed. The tool included more symptoms and more delineated time points. Next, a third

Sample

A purposive sample of 19 patients was included in the study, 12 females and 7 males. The median age of patients was 11 years (range, 1 to 16 years). The histological diagnoses included medulloblastoma, low-grade astrocytoma, pilocytic astrocytoma, ependymoma, oligodendroglioma, and high-grade glioma (not specified). Of the 19 patients represented in the study, 13 had ventriculoperitoneal shunts placed and 10 had postoperative intracranial pressure monitoring. Six of 19 patients had limited surgical resections at other hospitals but had not experienced the symptoms associated with the syndrome until the second surgery. All of the surgeries were performed at a large pediatric TABLE 1 Sample Characteristics

Patient No. 1 2 3 4

Diagnosis Oligodendroglioma Pilocytic astrocytoma

Gender

F F

Age 6 4 2 11

Surgery 1st 1st 2nd 1st

13

(Yd

Resection G-r NT GT GT

LOS lld

Shunt Y

Monitor Y

21d 13d 12d

N Y Y

N N Y

High-grade glioma Low-grade astrocytoma

F F

Pilocytic astrocytoma Pilocytic astrocytoma Medulloblastoma

M F F

2nd

NT

6d

N

4

Y

1st

NT

14d

N

Y

11

1st

GT

18d

Y

N

Medulloblastoma Ependymoma

F M

12 7

1st 1st

ST GT

9d 15d

Y N

11

Medulloblastoma Medulloblastoma

F M

12d 8d

Y Y

Y N

Medulloblastoma Medulloblastoma

M M

1st 2nd 1st

GT NT

12 13

1 10 5

Y Y

11

1st

ST ST

7d 14d

Y Y

N Y

14 15 16

Medulloblastoma Medulloblastoma

M M

Medulloblastoma Medulloblastoma

F F

1 11 11

1st 1st 2nd

NT GT NT

14d 8d 8d

Y Y Y

N N Y

13

2nd

GT

7d

N

Medulloblastoma Medulloblastoma

Y

F F

16 12

2nd 1st

GT GT

20d 7d

Y N

N N

5 6 7 8 9 10

17 18

19

Abbreviations, F, female; M, male; NT, near total; GT, gross total; ST, subtotal; LOS, length of hospital stay in days; Y, yes; N, no.

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nurse reviewer was invited to participate in the study. All three investigators met to discuss the tool and to review a medical record. To establish interrater agreement, the three investigators looked at pertinent sections of a medical record (medical progress notes, nurses’ notes and assessments, nutrition, and rehabilitation services documentation) to come to an agreement on the presence and stage of a symptom. For example, if in the physician’s notes he/she describes no gag or swallow elicited then the same was noted in nutrition and/or speech therapy assessment for presence of a symptom. Staging was measured by absent, minimal, moderate, and severe, based on the degree to which activ-

Patie”,

No.:

Initials:

Date of

Diagnosis:

surgery Date: Degree

Of Resection:

Shunt:

Y i N

Starting Weight:

1

STAGING 0 1 2 3

Diagno,sis:

ICP Monitor: Y i N

= = = =

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ities of daily living were affected by the symptoms of the syndrome (Figs 1 & 2). This instrument was pilot tested with the records of five patients. Issues regarding validity and symptoms of the posterior fossa syndrome were addressed and a final revision of the tool was completed. The data were then collected on the 19 patients in this study. Data Analysis The data from this study were analyzed using descriptive statistics, including frequency and percentage distributions for each symptom. Variables were described using measures of central tendency.

SYSTEM:

Absent Minimal Moderate Severe

DATA COLLECTION SHEET FOR POSTERIOR FOSSA SYNDROME

FIGURE

1.

Data collection tool.

Posterior

0

Absent

1

Minimal-symptom activities-of-daily-living Interventions.

2

Moderate-symptoms requires assistance

3

Severe-symptoms are incapacitating. total reliance upon treatment or Interventions to sustain and nutrition.

observable (ADL);

but does requires

readily apparent; and few interventions.

Fossa Syndrome

not affect no special

limits

ADLs;

care; ADLs

FIGURE 2.

Staging system. Findings

Postoperatively, in the intensive care unit, the child was able to (1) move purposefully, (2) focus on an object, and (3) make some attempts to verbalize even while intubated. However, within an average range of 24 to 107 hours the neurological status began to change without an identifiable factor such as a change in vital signs, intracranial pressure monitoring, or radiographic (computerized tomography; CT) abnormality. Facial weakness and nystagmus were observed as the initial symptoms to develop within a mean time of 24 to 27 hours, postoperatively. Two additional early symptoms were weakness of upper extremities and inability to follow verbal commands, both with 33 hours mean time. During the mean time range of 40 to 58 hours after surgery, several symptoms developed: (1) weakness of lower extremities, (2) emotional lability, (3) irritability, (4) random nonpurposeful movements of extremities, (5) difficulty verbalizing, and (6) mutism (Fig 3). Eighty-nine percent of the patients in this study experienced difficulty verbalizing (17 of 19). The next most common symptom was irritability (16 of 19, or 84%). Nystagmus was assessed in 79%, and mutism in 74%. Other common symptoms appear to be emotional lability (14 of 19, or 74% ), weakness of upper extremities (13 of 19, or 68%), and weakness of lower extremities (11 of 19, or 58% ) (Table 2). Ten of 19 children (53% ) had gross total removal of the posterior fossa tumor. Pathological diagnosis was variable: medulloblastoma (12 of 19, or 63%), pilocytic astrocytoma (3 of 19, or 16% ), oligodendroglioma (1 of 19, or 5% ), highgrade glioma (1 of 19, or 5% ), low-grade astrocytoma (1 of 19, or 5% ), and ependymoma (1 of

HmJ‘S

24

?4

44

M

FIGURE 3.

Mean time of onset of frequently occurring symptoms postoperatively. 19, or 5% ). Postoperatively, 10 patients (53%) had an intracranial pressure monitor. A shunt for hydrocephalus was placed in 68% of patients (13 of 19) (Table 1). Clinical Follow-up

After recognition of the posterior fossa syndrome, a multidisciplinary team was initiated to assist the child and family. Occupational therapy (12 of 19, or 63% ), physical therapy (14 of 19, or 74% ), and speech therapy (12 of 19, or 63% ) TABLE 2 Assessment of Symptoms Associated With Posterior Fossa Syndrome No. of Patients who Symptom

Experienced

Difficulty verbalizing Fussy, irritable Nystagmus Speech loss (mutism) Emotionally labile Weakness of upper extremities Weakness of lower extremities Institution of enteral/ parenteral feeds Inability to follow commands Random nonpurposeful movements of extremities Dysphagia Hemiparesis Facial weakness Absence of bladder control Absence of bowel control Impaired gag reflex Chewing movements lips/tongue * 3 patients

not toilet-trained

17 16 15 14 14 13 11

(% )

(89) (84) (79) (74) (74) (68) (58)

10 (53) 8 (42) 8 (42) 7 i37j 6 (32) 4(21) 4/16* (25) 3/16* (19) 3 (16)

201) before

surgery.

Mean Time of Onset in Hours (Range) 52 45 27 58 43 33 42

(24 to 120) (24 to 96) (24 to 96) (24 to 144) (24 to 96) (24 to 72) (24 to 96)

103 (24 to 192) 33 (24 to 72) 48 55 68 24 72 64 72

(24 to 96) (24 to 120) (24 to 168) (0 to 24) (24 to 96) (24 to 96) (48 to 120)

96 (96 to 120)

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were consulted for rehabilitation services. A thorough examination of the child’s vocal cords and swallowing was done as indicated. Ten children (53%) received enteral or parenteral feedings. Three of 19 children (16% ) were admitted to a rehabilitation facility after discharge from the hospital. One child went home and received outpatient rehabilitation services. The remaining children continued to receive rehabilitation services while undergoing chemotherapy and/or radiation therapy.

Discussion Our five most frequently identified symptoms were (1) difficulty verbalizing, (2) irritability, (3) nystagmus, (4) mutism, and (5) emotional lability. These findings are consistent with the literature, particularly with the speech disorder being identified as the most common symptom (Table 2). Furthermore, in our review it appears that nystagmus, weakness of upper extremities, and weakness of lower extremities may be the earliest symptoms of the posterior fossa syndrome. In recognizing posterior fossa syndrome, the investigators believe that these early findings are not as significant as the more delayed but more frequent language, emotional, and behavioral symptoms. In our clinical practice, these latter symptoms are very frustrating for both child and parents and are the last symptoms to resolve, although this has not been formally studied.

Implications for Nursing Practice Preparing parents for the possible onset of posterior fossa syndrome should be a part of preoperative teaching. Parents can become very anxious and fearful when the child develops these unexplained postoperative changes. In addition, it is important to explain all procedures, treatments, etc to the child with posterior fossa syndrome. The investigators believe children may be able to receive and process information adequately. Often the child is irritable and emotionally labile and typical comfort measures are futile. If the child is mute or has communication difficulties, the parents’ frustrations are increased. Strong family support and reassurance that the syndrome will improve can offer hope to

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the parents of children with posterior fossa syndrome. Early recognition of posterior fossa syndrome by the nursing staff is imperative. Children with posterior fossa syndrome need meticulous monitoring of intake and output, daily weights, safety precautions, skin care, and often early initiation of enteral or parenteral feedings. Nurses should give particular attention to charting gag reflex and swallowing assessment, voice characteristics, and cognitive abilities. Indication of symptom resolution assists in the discharge planning process. Critical pathways case management with a team approach is very beneficial for initiating rehabilitation services postoperatively and planning for discharge. A coordinated plan ensures that the child and family receive the necessary assistance to make the transition from the acute care facility.

Limitations of the Study One major limitation of this retrospective medical record review was that data collection depended on documentation from several health care providers (registered nurses in the Intensive Care Unit and Neuro Patient Care Unit, neurosurgery residents, rehabilitation therapists, and two neurosurgery staff physicians). Another limitation was that patients were intubated postoperatively for varying periods, therefore, assessment of vocalization could not be done at the same time interval. Soft wrist restraints were used on these patients while intubated, therefore, assessment of motor movement may have been limited. Postoperative effects of anesthesia and pain medication may have also influenced the neurological assessment, including speech. The data collection tool had 27 symptoms and 11 time frames for assessment. Only 17 of the 27 listed symptoms were analyzed (Table 2). This was due to several factors: (1) repetition of symptoms (dysphagia; impaired swallowing), (2) some items were not symptoms (presence of tracheostomy, weight, rehabilitation, etc), and (3) some symptoms were not documented in any patients (fever >38”C, neck stiffness, hoarseness). Assessment of time frame was not done after 21 days. All patients were discharged to another facility for further treatment or rehabilitation by

Posterior

187

Fossa Syndrome

that time point. Collecting and analyzing data for the exact duration of the symptoms was beyond the scope of this study. Severity of symptoms was not adequately assessed in this study. The tool had a four-level staging for severity assessment but limitations of documentation did not allow for accurate retrospective review and interpretation.

Future Research A follow-up study of these same 19 children could focus on specific outcomes such as duration of symptoms and neurodevelopmental status, which has been serially assessed. Other work could evaluate specific tumor location within the posterior fossa, follow-up diagnostic images, surgical approach, degree of surgical resection, and other factors. Evaluating outcomes from specific nursing interventions in this population would also be of great benefit and add to the very limited literature currently available. A specific example would be comparing routes of administering feedings to daily weights during the postoperative period. The study data collection tool could be used with other samples of children with posterior

fossa syndrome to further establish its reliability and validity. Comparative studies on the frequency of symptoms related to the syndrome, their intensity and duration, could then be conducted to further the scope of this syndrome.

Conclusion It is our postulation that posterior fossa syndrome is variable both in symptomatology and duration. The most common triad of symptoms: speech difficulty, increased irritability, and nystagmus seems to be indicative of a posterior fossa syndrome in children after posterior fossa brain tumor surgery. Early recognition of posterior fossa syndrome and anticipatory nursing care of these children may significantly improve outcome. There remains a myriad of questions about this syndrome and a potential wealth of clinical research studies that need to be conducted.

Acknowledgment The authors would like to thank Kerry Palmertree, MLS, MIS, Health Sciences Library, Le Bonheur Children’s Medical

Center for his valuable

assistance.

References 1. Heideman RL, Packer RJ, Albright LA, et al: Tumors of the central nervous system, in Pizzo PA, Poplack DG (eds): Principles and Practice of Pediatric Oncology. Philadelphia, PA, Lippincott, 1993, pp 633-681 2. Bonner K, Siegel KR: Pathology, treatment and management of posterior fossa brain tumors in childhood. J Neurosci Nurs 20:84-93, 1988 3. Hudgins RJ, Edwards MSB: Management of infratentorial brain tumors. Pediatr Neurosci 13:214-222, 1987 4. Packer RJ, Sposto R, Atkins TE, et al: Quality of life in children with primitive neuroectodermal tumors (medulloblastoma) of the posterior fossa. Pediatr Neurosci 13:169175, 1987 5. Kun LE, Kovnar EH, Sanford RA: Ependymomas in children. Pediatr Neurosci 14:57-63, 1988 6. Farwell JR, Dohrman GJ, Flannery JT: Central nervous system tumors in children. Cancer 40:3123-3132, 1977 7. Griffin TW, Beaufait D, Blasko JC: Cystic cerebellar astrocytoma in childhood. Cancer 44:276-280, 1979 8. Sanford RA, Muhlbauer MS, Kirk EA: Multiple-discipline approach improves brain tumor treatments. LBonheur Access 7~6-7, 1992 9. Evans AE, Jenkin RDT, Sposto R, et al: The treatment of medulloblastoma: Results of a prospective randomized trial of radiation therapy with and without CCNU, vincristine, and prednisone. J Neurosurg 72:572-582, 1990 10. Mulhern RK, Horowitz ME, Kovnar EH, et al: Neurode-

velopmental status of infants and young children treated for brain tumors with preirradiation chemotherapy. J Clin Oncol 7:1660-1666, 1989 11. Humphreys RP: Mutism after posterior fossa tumor surgery. Concepts Pediatr Neurosurg 9:57-64, 1989 12. Rekate HL, Grubb RL, Aram DM, et al: Muteness of cerebellar origin. Arch Neural 42:697-698, 1985 13. Salvati M, Missori P, Lunardi P, et al: Transient cerebellar mutism after posterior cranial fossa surgery in an adult. Clin Neurol Neurosurg 93:313-316, 1991 14. Catsman-Berrevoets CE, van Dongen HR, Zwetsloot CP: Transient loss of speech followed by dysarthria after removal of posterior fossa tumour. Dev Med Child Neurol 34:1102-1117, 1992 15. Ferrante L, Mastronardi L, Acqui M, et al: Mutism after posterior fossa surgery in children. J Neurosurg 72959-963, 1990 16. Dietze DD, Mickle JP: Cerebellar mutism after posterior fossa surgery. Pediatr Neurosurg 91:25-31, 1990 17. Crutchfield JS, Sawaya R, Meyers CA, et al: Postoperative mutism in neurosurgery. J Neurosurg 81:115-121, 1994 18. Wisoff JH, Epstein FJ: Pseudobulbar palsy after posterior fossa operation in children. Neurosurgery 15:707-709, 1984 19. Woods NF, Catanzaro M: Nursing Research: Theory and Practice. St Louis, MO, Mosby, 1988