Hoofdstuk 16 Trigeminus letsels

16.1 Chronologie van degeneratie en regeneratie

16.2 Neurosensorische testen

Level A: Spatiotemporal Sensory Perception1 Level B: Contact Detection2 Level C: Pain Threshold and Tolerance3
Normal Present Present Present
Mild Failed Present Present
Moderate Failed Failed Present
Severe Failed Failed Elevated
Complete Failed Failed Absent

1 Direction Sensitivity <90%, Static 2-Point Discrimination <18 mm
2 Monofilament <2.83
3 Pressure Pain Tolerance <2.0 lb (<1 kg), Pressure Pain Threshold <1.5 lb (680 gram), Heat Temperature Threshold <47°C, Heat Temperature Tolerance <50°C

16.3 Neurosensorische flowchart

QST Flowchart

Figure 16.1: QST Flowchart

MRCS
S0 Afwezigheid van gevoel in het autonome gebied van de zenuw
S1 Herstel van diepe cutane pijn en tactiele gevoeligheid
S1+ Herstel van oppervlakkige pijngevoeligheid
S2 Herstel van een zekere mate van oppervlakkige cutane pijn en tactiele gevoeligheid
S2+ Zoals in S2, maar met een overdreven reactie
S3 Terugkeer van pijn en tactiele gevoeligheid met verdwijnen van overrespons, statische 2PD>15mm, bewegende 2PD>7mm
S3+ Terugkeer van gevoel zoals in S3 met enig herstel van tweepuntsdiscriminatie, statische 2PD: 7-15mm, bewegende 2PD: 4-7mm
S4 Volledig herstel, statische 2PD: 2-6mm, bewegende 2PD: 2-3mm

16.4 Correlatie van Sunderland - NST - Chirurgie - MRN

Sunderland Classification Clinical NST Level and MRCS Grade Description Surgical Findings by Direct Inspection MRN Findings
I Normal (4)/S3+ or S4 by 3 mo Intact with no internal or external fibrosis, normal mobility, and neuroarchitecture (visualized fascicles and Fanconi bands) Anatomic: homogenous, mild increased T2W nerve signal
II Normal (4)/S3+ or S4 by 6 mo Intact with no internal fibrosis; external fibrosis, restricted mobility, but neuroarchitecture intact (visualized fascicles and Fanconi bands once external scar removed) Anatomic: homogenous increased T2W signal of nerve and mild nerve thickening or constriction; perineural fibrosis
III Mild (3) or moderate (2)/S2, S2+, S3 by ≥6 mo Intact with both internal and external fibrosis, restricted mobility, and disturbance of neuroarchitecture (abnormal fascicle patterns and/or Fanconi bands not visible) Anatomic: homogenous increased T2W signal of nerve and moderate thickening or constriction; perineural fibrosis
IV Moderate (2) or severe (1)/S1, S2, S2+ by ≥6 mo Partially transected nerve but some amount of distal nerve present with or without neuroma in continuity Anatomic: heterogeneous T2W signal of nerve and neuroma in continuity; perineural and intraneural fibrosis
V Severe (1) or complete (0)/S0, S1 by ≥6 mo Completely transected nerve with or without amputation neuroma Anatomic: discontinuous nerve with end-bulb neuroma

16.5 Stratificatie op basis van MRN en chirurgie

Criteria for stratifying of nerve injuries on MRN and surgery based on Sunderland classification

Class MRN Surgical
I

Qualitative: Homogeneous increased T2 signal of nerve with no change in caliber

Quantitative: No changes

Intact with no internal or external fibrosis, normal mobility and neuroarchitecture (visualize fascicles and Fanconi bands)
II

Qualitative: Homogeneous increased T2 signal of nerve and mild nerve thickening Perineural fibrosis

Quantitative: <50% larger than contralateral /normal nerve

Intact with no internal fibrosis with external fibrosis, restricted mobility but neuroarchitecture intact (visualized fascicles and Fanconi bands once external scar removed)
III

Qualitative: Homogeneous increased T2 signal of nerve and moderate to marked nerve thickening Perineural fibrosis

Quantitative: >50% larger than contralateral/normal nerve

Intact with both internal and external fibrosis, restricted mobility and disturbance of neuroarchitecture (abnormal fascicle patterns and/or Fanconi bands not visible)
IV

Qualitative: Heterogeneous increased T2 signal of nerve and focal enlargement in otherwise continuous nerve (neuroma in continuity) Perineural and intraneural fibrosis

Quantitative: Focal swelling with heterogeneous T2 signal or fascicular disruption

Partial transected nerve, but some amount of distal nerve present with or without lateral neuroma
V

Qualitative: Discontinuous nerve with end-bulb neuroma

Quantitative: Complete disruption with gap and end-bulb neuroma

Completely transected nerve with or without amputation (end-bulb) neuroma

16.6 MRN bevindingen case verus control IAN-LN-schade

Differences in thickness, T2SIR, and CNR among the case and control groups

Nerve Thickness Thickness T2SIR T2SIR CNR CNR
Group Mean Difference P Value Mean Difference P Value Mean Difference P Value
IAN Cases 0.60 (0.33) 0.01 3.15 (1.91) 0.012 6.53 (4.00) 0.01
IAN Controls 0.22 (0.20) 0.01 1.34 (1.09) 0.012 2.20 (1.89) 0.01
LN Cases 0.87 (0.34) 0.0001 4.58 (3.40 0.005 6.93 (4.89) 0.01
LN Controls 0.11 (0.12) 0.0001 1.92 (1.51) 0.005 3.37 (3.81 0.01