Appendix II
Round 1 - Statements and Voting Results
R1Q1 – Cerebellar Mutism (CM) refers to transient loss or severe reduction of speech
that follows lesions of the cerebellum as opposed to the cerebrum or lower cranial
nerves. Its unique features are delayed onset (1 - 7 days) and limited duration (1 day 2 or more years) followed by a recovery period where speech is marked by dysarthria.
Strongly agree
Agree
Agree with amendment
Not sure if I agree or disagree
Disagree (but really agree w/amendment)
14/27
7/27
5/27
0/27
1/27
(51.85%)
(25.93%)
(18.52%)
(0.00%)
(3.70%)
Support 96%
R1Q2 – CM is the hallmark characteristic of the more broad Posterior Fossa
Syndrome (PFS)
Strongly agree
Agree
Agree w/amendment
Not sure if I agree or disagree
Disagree
10/27
12/27
2/27
0/27
3/27
(37.04)
(44.44%)
(7.41%)
(0.00%)
(11.11%)
Support 89%
R1Q3 - Symptoms of the PFS may occur within neuropsychological, neuropsychiatric
and neurological domains, and are characterized by:
 language- and speech-related problems, including CM (see Q1 and Q2)
 cognitive impairment
 affective or behavioral symptoms or both
 motor problems
Strongly agree
Agree
Agree w/amendment
Not sure if I agree or disagree
Disagree
13/27
11/27
1/27
1/27
1/27
(48.15%)
(40,74%)
(3.70%)
(3,70%)
(3,70%)
Support 93%
R1Q4 - In addition to typical cerebellar signs (e.g. ataxia of gait, hypotonia, tremor,
nystagmus), motor problems of the PFS can include hemiparesis and cranial nerve
palsies.
Strongly agree
Agree
Agree w/amendment
6/27
8/27
1/27
(22,22%)
(29,63%)
(3.70%)
Not sure if I agree or disagree
Disagree
7/27
5/27
(25.93%)
(18,52%)
Support 56%
R1Q5 – Symptoms of the PFS may occur in different combinations and may vary in
severity (NB one respondent skipped this question)
Strongly agree
Agree
Agree with amendment
Not sure if I agree or disagree
Disagree
17/26
8/26
1/26
0/26
0/26
(65.38%)
(30,77%)
(3.85%)
(0.00%)
(0.00%)
Support 100%
R1Q6 - The PFS is most commonly observed in children. It is rarely seen in adults.
Strongly agree
Agree
Agree with amendment
Not sure if I agree or disagree
Disagree
7/27
11/27
1/27
5/27
3/27
(25.93%)
(40.74%)
(3.70%)
(18.52%)
(11.11%)
Support 70%
R1Q7 - The PFS is most commonly observed after posterior fossa tumor surgery, but
may also occur following trauma, vascular incidents and infections.
Strongly agree
Agree
Agree with amendment
Not sure if I agree or disagree
Disagree
12/27
6/27
0/27
6/27
3/27
(44.44%)
(22.22%)
(0,00%)
(22.22%)
(11.11%)
Support 67%
R1Q8 - In order to be diagnosed with the PFS, a patient needs to have CM +
symptoms belonging to at least 2 out of the 3 following categories: cognitive,
affective/ behavioral, motor.
Strongly agree
Agree
Agree with amendment
Nor sure if I agree or disagree
Disagree
Support 59%
4/27
10/27
2/27
4/27
7/27
(14.81%)
(37.04%)
(7.41%)
(14.81%)
(25.93%)
R1Q9 - To aid diagnosis, the following is recommended pre- and post-operatively in
tumor patients and as soon as the PFS is suspected in non-tumor patients:
 MRI, preferably also DWI and DTI
 Full neurological examination
 Psychiatric evaluation (important to exclude delirium)
 Neuropsychological testing
 Speech and language assessment
 Systematic scoring of PFS symptoms with a specific PFS scoring scale (more
about such a scale in Round 2)
Strongly agree
Agree
Agree with amendment
Not sure if I agree or disagree
Disagree
9/27
9/27
4/27
2/27
3/27
(33.33%)
(33.33%)
(14.81%)
(7,41%)
(11,11%)
Support 81%
R1Q10 - This first round has been dedicated to definition and diagnosis of PFS and
CM. Round two will focus on monitoring of acute and late sequelae (follow-up) and
the need for a new PFS scoring scale, but it will also allow for voting on other topics.
Are there any other important statements that you think we should include?
No
Yes
20/27 (76.92%)
6/27 (23.08%)
Suggested topics from respondents
The effects of different surgical methods; description of specific neurologic
symptoms; duration of symptoms; standardized testing of speech and processing
speed; PFS as subtype of CCAS; how to avoid the syndrome; the most accurate terms
to be used for the mutism versus cognitive and behavioral features and motor
disabilities.
Round 2 - Statements and Voting Results
Modifications in statements from R1 that were presented again in R2 are written in
italics.
R2Q1 (modified) - Cerebellar Mutism (CM) refers to transient loss or severe
reduction of speech that follows lesions of the cerebellum as opposed to the cerebrum
or lower cranial nerves. It often includes delayed onset (1 – 7 days), and is further
characterized by limited duration (1 day - 2 or more years) followed by a recovery
period where speech is marked by dysarthria.
Strongly agree
Agree
Agree with amendment
Not sure if I agree or disagree
Disagree
11/29
14/29
3/29
1/29
0/29
(37.93%)
(48.28%)
(10.34%)
(3.45%)
(0.00%)
Support 96%
R2Q2 (modified) - The PFS is most commonly reported in children after posterior
fossa tumor surgery, but adult cases have also been described (though less
frequently).
Strongly agree
Agree
Agree with amendment
Not sure if I agree or disagree
Disagree
11/29
15/29
0/29
3/29
0/29
(37.93%)
(51.72%)
(0.00%)
(10.34%)
(0,00%)
Support 90%
R2Q3 (new) - The relationship between Mutism and Pseudobulbar Palsy, Cerebellar
Mutism (CM), Mutism and Subsequent Dysarthria (MSD), Cerebellar Mutism
Syndrome (CMS) and the Cerebellar Cognitive Affective Syndrome (CCAS) needs
clarification.
Strongly agree
Agree
Agree with amendment
Not sure if I agree or disagree
Disagree
15/29
11/29
1/29
2/29
0/29
(51.72%)
(37.93%)
(3.45%)
(6.90%)
(0,00%)
Support 93%
R2Q4 (modified) - To aid diagnosis of the PFS, the following is recommended preoperatively in patients who are to undergo surgery for a posterior fossa tumor:
Mandatory
 Full neurological examination
 MRI, preferably with DWI and DTI sequences
 Systematic scoring of PFS symptoms with a specific PFS scoring scale
Optional
 Psychiatric evaluation (to exclude delirium)
 Brief/focused neuropsychological testing
 Brief speech and language assessment
Strongly agree
Agree
Agree with amendment
Not sure if I agree or disagree
Disagree
Support 86%
8/29
12/29
5/29
2/29
2/29
(27.58%)
(41.38%)
(17.24%)
(6.90%)
(6.90%)
R2Q5 (modified) - In addition to typical cerebellar signs (e.g. ataxia , hypotonia,
tremor, nystagmus), motor problems of the PFS can also include hemiparesis and
cranial nerve palsies in case of brainstem involvement.
Strongly agree
Agree
Agree with amendment
Not sure if I agree or disagree
Disagree
8/29
11/29
1/29
7/29
2/29
(27.58%)
(37.93%)
(3.45%)
(24.14%)
(6.90%)
Support 69%
R2Q6 (new) - For diagnostic and follow-up purposes, a new formal PFS scoring scale
is needed to assess the presence, severity and duration of common symptoms within
all domains of the PFS:
 Language- and speech-related problems (including CM)
 Cognitive features
 Affective/behavioral features
 Motor/neurological features
Strongly agree
Agree
Agree with amendment
Not sure if I agree or disagree
Disagree
16/29
10/29
2/29
1/29
0/29
(55.17%)
(34.48%)
(6.90%)
(3.45%)
(0,00%)
Support 97%
R2Q7 (new) - To ensure feasibility, this scale needs to be:
 Brief
 Sensitive and specific
 Valid and reliable
 Applicable to both children and adults
 Suited to bedside assessment of a potentially uncooperative patient, and to
later follow-up assessments at different time points
 Easily and reliably administered by different professionals alike (doctors,
nurses, neuropsychologists etc.) with limited inter-rater variation
Strongly agree
Agree
Agree with amendment
Not sure if I agree or disagree
Disagree
17/29
8/29
2/29
2/29
0/29
(58.62%)
(27.58%)
(6.90%)
(6.90%)
(0.00%)
Support 93%
R2Q8 (new) - To assess prognosis, the scale needs to allow for:
 Grading of the severity of symptoms
 Documenting the duration of symptoms
Strongly agree
Agree
Agree with amendment
Not sure if I agree or disagree
Disagree
17/29
9/29
0/29
2/29
1/29
(58.62%)
(31.03%)
(0.00%)
(6.90%)
(3.45%)
Support 90%
R2Q9 There was disagreement/confusion within the selection committee about the
following statements (A-F). This may have been due to wording or phrasing, and
indicates in any case a need for further debate around the issues they address. We will
not be voting on them now, but have the opportunity to discuss them in further detail
during the consensus meeting. Would you care to comment on any of them now?
A - In order to be diagnosed with the Posterior Fossa Syndrome (PFS), a patient needs
to have CM + symptoms belonging to at one (as opposed to two) out of the following
categories:
 Cognitive
 Affective/behavioral
 Motor
B - Motor problems of the PFS can also include more specific neurological symptoms
like transient cerebellar eye closure, cortical blindness, compulsive pre-sleep disorder,
urinary retention/incontinence.
C - The cognitive, affective and linguistic symptoms of the PFS (excluding CM and
motor signs) are the same as those of the Cerebellar Cognitive Affective Syndrome
(CCAS), described by Schmahmann and Sherman in 1997.
D - Cognitive, affective and linguistic problems that have been described in pediatric
and adult patients following trauma, vascular incidents and infections represent the
CCAS (not the PFS).
E - The PFS can be described as a severe post-operative manifestation of the CCAS,
which in addition to cognitive and affective symptoms also includes CM and (often
specific) motor signs.
F - In research context, the following is recommended at regular intervals during the
first 2 years post-diagnosis of the PFS:
 MRI
 PFS scoring scale
 Psychiatric evaluation
 Full neurological examination
 Language and speech testing
 Detailed neuropsychological testing
 QOL assessment with PedsQL
Round 3 - Statements and Voting Results
R3Q1. Post-operative Pediatric CMS is characterized by delayed onset
mutism/reduced speech and emotional lability after cerebellar or 4th ventricle tumor
surgery in children.
Strongly agree
Agree
Agree with amendment
Not sure if I agree or disagree
Disagree
23/30 (76.66%)
7/30 (23.33%)
0/30 (0.00%)
0/30 (0.00%)
0/30 (0.00%)
100% support
R3Q2. Additional common features include hypotonia and oropharyngeal
dysfunction/dysphagia.
Strongly agree
Agree
Agree with amendment
Not sure if I agree or disagree
Disagree
15/30 (50.00%)
11/30 (36.66%)
0/30 (0.00%)
4/30 (13.33%)
0/30 (0.00%)
87% support
R3Q3. It may frequently be accompanied by the cerebellar motor syndrome,
cerebellar cognitive affective syndrome and brain stem dysfunction including long
tract signs and cranial neuropathies
Strongly agree
Agree
Agree with amendment
Not sure if I agree or disagree
Disagree
15/30 (50.00%)
14/30 (46.66%)
0/30 (0.00%)
1/30 (3.33%)
0/30 (0.00%)
97% support
R3Q4. Although recovery may be prolonged, the mutism is always transient; other
deficits often persist. Mutism recovers, but speech and language do not become
normal
Strongly agree
Agree
Agree with amendment
Not sure if I agree or disagree
Disagree
83% support, but many comments on wording
12/30 (40.00%)
12/30 (40.000%)
3/30 (10.00%)
2/30 (6.66%)
1/30 (3.33%)
Round 4 - Statement and Voting Results
R4Q1 (modified from R3). The mutism is always transient, but recovery from CMS
may be prolonged. Speech and language may not return to normal, and other deficits
of cognitive, affective and motor function often persist.
Strongly agree
Agree
Agree with amendment
Not sure if I agree or disagree
Disagree
97% support
17/29 (58.62%)
9/29 (31.03%)
2/29 (6.90%)
1/29 (3.45%)
0/29 (0.00%)